REVIEW | doi:10.20944/preprints202008.0069.v1
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; zoonoses; anthroponosis; veterinarian; OIE and animals
Online: 3 August 2020 (10:12:55 CEST)
Coronavirus disease is the current cause of global concern. The massive outbreak of COVID-19 has led the World Health Organization (WHO) to declare this as a pandemic situation. The Severe Acute Respiratory Syndrome Coronavirus-2 (SARSCoV-2) is responsible for COVID-19 leading to acute respiratory distress and substantial mortality in humans. However, the first laboratory confirmation of SARS-CoV-2 in a pet dog in Hong Kong has shown the possibility of human-to-animal transmission (zooanthroponotic) of the virus. Thereafter, many animals including cat, tiger, lion and mink have also been reported to acquire the virus in several countries. In this situation the role of veterinarian assumes important in treating the animals, helping in food security, disease diagnosis, surveillance and boosting the economy of livestock stakeholders at the grassroot level. In the absence of any selective vaccine or drug against SARS-CoV-2, the world is anticipated to triumph over this pandemic with collaborative, multisectoral, and transdisciplinary approach linking human, animal and environmental health. This article gives an insight into the confirmed SARS-CoV-2 outbreaks in animals, including the factors behind the shuffling of the virus among variety of species and also emphasizes on the role of veterinarian in managing and safeguarding public health so as to pave the way for adopting one health approach in order to conserve biodiversity.
Sun, 2 August 2020
REVIEW | doi:10.20944/preprints202008.0032.v1
Subject: Life Sciences, Virology Keywords: COVID-19; immunosuppression; malnutrition; cytokine storm; SARS-CoV-2; coronavirus
Online: 2 August 2020 (13:02:10 CEST)
Seven human coronaviruses are known to infect humans. The most recent one, SARS-CoV-2, was isolated and identified in January 2020 from a patient presenting with severe respiratory illness in Wuhan, China. Even though viral coinfections have the potential to influence the resultant disease pattern in the host, very few studies have looked at the disease outcomes in patients infected with both HIV and hCoVs. Groups are now reporting that even though HIV-positive patients can be infected with hCoVs, the likelihood of developing severe CoV-related diseases in these patients is often similar to what is seen in the general population. This review aimed to summarize the current knowledge of coinfections reported for the HIV and hCoVs. Also, based on the available data, this review aimed to theorize why HIV-positive patients do not frequently develop severe CoV-related diseases.
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; spike protein; ACE1; ACE2; host-virus interaction; drug repurposing
Online: 2 August 2020 (09:23:18 CEST)
Respiratory transmission is the primary route of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. Angiotensin I converting enzyme 2 (ACE2) is the known receptor of SARS-CoV-2 surface spike glycoprotein for entry into human cells. A recent study reported absent to low expression of ACE2 in a variety of human lung epithelial cell samples. Three bioprojects (PRJEB4337, PRJNA270632 and PRJNA280600) invariably found abundant expression of ACE1 (a homolog of ACE2 and also known as ACE) in human lungs compared to very low expression of ACE2. In fact, ACE1 has a wider and more abundant tissue distribution compared to ACE2. Although it is not obvious from the primary sequence alignment of ACE1 and ACE2, comparison of X-ray crystallographic structures show striking similarities in the regions of the peptidase domains (PD) of these proteins, which is known (for ACE2) to interact with the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. Critical amino acids in ACE2 that mediate interaction with the viral spike protein are present and organized in the same order in the PD of ACE1. In silico analysis predicts comparable interaction of SARS-CoV-2 spike protein with ACE1 and ACE2. In addition, this study predicts from a list of 1263 already approved drugs that may interact with ACE2 and/or ACE1, potentially interfere with the entry of SARS-CoV-2 inside the host cells and alleviate the symptoms of Coronavirus disease (COVID-19).
Fri, 31 July 2020
ARTICLE | doi:10.20944/preprints202007.0749.v1
Subject: Life Sciences, Virology Keywords: Bovine coronavirus; intersititial pneumonia; phylogenetic analysis; Real time PCR
Online: 31 July 2020 (13:46:21 CEST)
An outbreak of winter disease, complicated by severe respiratory syndrome, occurred in January 2020 in a high production dairy cow herd located in a hilly area of the Calabria region. Of the 52 animals belonging to the farm, 5 (9.6%) died with severe respiratory distress, death occurring 3-4 days after the appearance of the respiratory signs (caught and gasping breath). Microbiological analysis revealed absence of pathogenic bacteria whilst Real-time PCR identified the presence of RNA from Bovine Coronavirus (BCoV) in several organs: lungs, small intestine (jejunum), mediastinal lymph nodes, liver and placenta. Since being the only pathogen identified, BCoV was hypothesized to be the cause of the lethal pulmonary infection. Like the other CoVs, BCoV is able to cause different syndromes. Its role in calfhood diarrhoea and in mild respiratory disease is well known: we report instead the involvement of this virus in a severe and fatal respiratory disorder, with symptoms and disease evolution resembling that of Severe Acute Respiratory Syndromes (SARS).
ARTICLE | doi:10.20944/preprints202007.0747.v1
Subject: Life Sciences, Virology Keywords: African swine fever virus; virulence; pathology; wild boar; domestic pig; macroscopy; histopathology; immunology
Online: 31 July 2020 (13:01:32 CEST)
Endemically infected European wild boar are considered a major reservoir of African swine fever virus in Europe. While high lethality was observed in the majority of field cases, strains of moderate virulence occurred in the Baltic States. One of these, “Estonia 2014”, led to a higher number of clinically healthy, antibody-positive animals in the hunting bag of North-Eastern Estonia. Experimental characterization showed high virulence in wild boar but moderate virulence in domestic pigs. Putative pathogenic differences between wild boar and domestic pigs are unresolved and comparative pathological studies are limited. We here report on a kinetic experiment in both subspecies. Three animals each were euthanized at 4, 7 and 10 days post infection (dpi). Clinical data confirmed higher virulence in wild boar although macroscopy and viral genome load in blood and tissues were comparable in both subspecies. The percentage of viral antigen positive myeloid cells tested by flow cytometry did not differ significantly in most tissues. Only immunohistochemistry revealed consistently higher viral antigen loads in wild boar tissues in particular 7 dpi, whereas domestic pigs already eliminated the virus. The moderate virulence in domestic pigs could be explained by a more effective viral clearance.
Thu, 30 July 2020
REVIEW | doi:10.20944/preprints202007.0712.v1
Subject: Life Sciences, Virology Keywords: Group-B Enterovirus; RNA domain-I; viral ribonucleoprotein complexes; Enterovirus replication; 5’ terminally deleted viral forms; antiviral innate immune response; type I Interferon
Online: 30 July 2020 (10:00:13 CEST)
Group-B enteroviruses (EV-B) are ubiquitous naked single-stranded positive RNA viral pathogens that are responsible for common acute or persistent human infections. Their genome is composed in the 5'end by a non-coding region, which is crucial for the initiation of the viral replication and translation processes. RNA domain-I secondary structures can interact with viral or cellular proteins to form viral ribonucleoprotein (RNP) complexes regulating viral genomic replication, whereas RNA domains-II to -VII (IRES) are known to interact with cellular ribosomal subunits to initiate the viral translation process. Natural 5’ terminally deleted viral forms lacking some genomic RNA domain-I secondary structures have been described in EV-B induced murine or human infections. Recent in vitro studies have evidenced that the loss of some viral RNP complexes in the RNA domain-I can modulate the viral replication and infectivity levels in EV-B infections. Moreover, the disruption of secondary structures of RNA domain-I could impair viral RNA sensing by RIG-I or MDA5 receptors, a way to overcome antiviral innate immune response. Overall, natural 5′ terminally deleted viral genomes resulting in the loss of various structures in the RNA domain-I could be major key players of host-cell interactions driving the development of acute or persistent EV-B infections.
Wed, 29 July 2020
Subject: Life Sciences, Virology Keywords: Tap water; human adenovirus; enteroviruses; rotavirus; viral gastroenteritis
Online: 29 July 2020 (17:42:52 CEST)
Drinking water supplies in the developing world often serve as a biosphere for various organisms. Viral gastroenteritis is a neglected area of research in Pakistan, there is no data for the prevalence of enteric viruses in drinking water of the largest city of Karachi. The present study aimed to provide a survey of the existence of enteric viruses: human adenovirus (HAdV), human enteroviruses (hEV), and genotype A rotavirus (GARV) in tap water. Using a simple PCR approach, we detected 20%, 43%, and 23% of HAdV, hEV, and GARV in tap water respectively. We have also shown an overall quality of tap water at the pumping station and consumer tap. Moreover, we assessed the efficiency of small-scale water treatment methods for the removal of viruses.
Fri, 24 July 2020
REVIEW | doi:10.20944/preprints202007.0587.v1
Subject: Life Sciences, Virology Keywords: Keywords: COVID-19; SARS-CoV-2; SARS-CoV; Accessory Protein; ORF8; ORF8ab
Online: 24 July 2020 (13:51:12 CEST)
COVID-19 pandemic in first seven months has led to more than 15 million confirmed infected cases and 600,000 deaths. SARS-CoV-2, the causative agent for COVID-19 has proved a great challenge for its ability to spread in asymptomatic stages and a diverse disease spectrum it has generated. This has created a challenge of unimaginable magnitude not only affecting human health and life but also potentially generating a long-lasting socioeconomic impact. Both medical sciences and biomedical research have also been challenged consequently leading to a large number of clinical trials and vaccine initiatives. While known proteins of pathobiological importance are targets for these therapeutic approaches, it is imperative to explore other factors of viral significance. Accessory proteins are one such trait that have diverse roles in coronavirus pathobiology. Here we analyze certain genomic characteristics of SARS-CoV-2 accessory protein ORF8, predict upon its protein features and review current available literature regarding its function. We have also undertaken review of ORF8 homolog ORF8ab from SARS-CoV with a purpose of developing holistic understanding of these proteins for reason that coronaviruses have been infecting humans repeatedly and might continue to do so. Despite low nucleotide and protein identity and differentiating genome level characteristics, there appears to be significant structural integrity and functional proximity between these proteins pointing towards their high significance. There is further need for comprehensive genomics and structural-functional studies to lead towards definitive conclusions regarding their criticality and that can eventually define their relevance to therapeutics development.
Thu, 23 July 2020
ARTICLE | doi:10.20944/preprints202007.0551.v1
Subject: Life Sciences, Virology Keywords: Coronavirus; COVID-19; SARS-CoV-2; SARS-CoV; MERS-CoV; Antiviral therapy
Online: 23 July 2020 (11:43:46 CEST)
Background: To prioritize the development of antiviral compounds, it is necessary to compare their relative preclinical activity and clinical efficacy. Methods: We reviewed in vitro, animal model, and clinical studies of candidate anti-coronavirus compounds and placed extracted data in an online relational database. Results: As of July 2020, the Coronavirus Antiviral Research Database (CoV-RDB; covdb.stanford.edu) contained >2,400 cell culture, entry assay and biochemical experiments, 240 animal model studies, and 56 clinical studies from >300 published papers. SARS-CoV-2, SARS-CoV, and MERS-CoV account for approximately 85% of the data. Approximately 75% of experiments involved compounds with a known or likely mechanism of action, including receptor binding inhibitors and monoclonal antibodies (20%); viral protease inhibitors (18%); polymerase inhibitors (9%); interferons (8%); fusion inhibitors (8%); host endosomal trafficking inhibitors (7%); and host protease inhibitors (5%). For 724 compounds with a known or likely mechanism, 95 (13%) are licensed in the US for other indications, 72 (10%) are licensed outside the US or are in human trials, and 557 (77%) are pre-clinical investigational compounds. Conclusion: CoV-RDB facilitates comparisons between different candidate antiviral compounds, thereby helping scientists, clinical investigators, public health officials, and funding agencies prioritize the most promising compounds and repurposed drugs for further development.
Tue, 21 July 2020
ARTICLE | doi:10.20944/preprints202007.0475.v1
Subject: Life Sciences, Virology Keywords: Mathematical model; SARS; COVID-19; Superspreaders; Viral outbreaks; H7N9; Influenza; zoonotic
Online: 21 July 2020 (10:48:12 CEST)
Despite great advances in understanding the dynamics of viral epidemics, the emergence of rapidly spreading, highly pathogenic viruses remains a realistic and catastrophic possibility, which current health systems may not be able to fully contain. An intriguing feature in many recent zoonotic viral outbreaks is the presence of ‘superspreaders’, which are infected individuals that cause dramatically more new cases than the average. Here I study the effect of superspreaders on the early dynamics of emerging viruses that have not gained the capacity for efficient human-to-human transmission, i.e viruses with R0 < 1. I show that superspreaders have a higher chance of rapid extinction, but under ‘crowded’ conditions can lead to ‘outbreaks’, causing far more cases than regular viruses. Hence I suggest that outbreaks of highly pathogenic superspreaders are more likely when they coincide in time and space with an unrelated outbreak leading to increased hospital admission rates. These superspreader outbreaks may be difficult to detect, especially in the context of a different epidemic in progress, and can significantly affect mortality patterns observed in affected areas.
Mon, 20 July 2020
REVIEW | doi:10.20944/preprints202007.0471.v1
Subject: Life Sciences, Virology Keywords: bathing waters; coronavirus; environmental transmission; faecal-oral route; infection risk; waterborne illness
Online: 20 July 2020 (12:02:45 CEST)
The recent detection of SARS-CoV-2 RNA in feces has led to speculation that it can be transmitted via the fecal-oral/ocular route. This review aims to critically evaluate the incidence of gastrointestinal (GI) symptoms, the quantity and infectivity of SARS-CoV-2 in feces and urine, and whether these pose an infection risk in sanitary settings, sewage networks, wastewater treatment plants, and the wider environment (e.g. rivers, lakes and marine waters). Overall, severe GI dysfunction is only evident in a small number of COVID-19 cases, with 11 ± 2% exhibiting diarrhea and 12 ± 3% exhibiting vomiting and nausea. In addition to these cases, SARS-CoV-2 RNA can be detected in feces from some asymptomatic, mildly- and pre-symptomatic individuals. Fecal shedding of the virus peaks in the symptomatic period and can persist for several weeks, but with declining abundances in the post-symptomatic phase. SARS-CoV-2 RNA is occasionally detected in urine, but reports in fecal samples are more frequent. The abundance of the virus genetic material in both urine (ca. 102-105 gc/ml) and feces (ca. 102-107 gc/ml) is much lower than in nasopharyngeal fluids (ca. 105-1011 gc/ml). There is strong evidence of multiplication of SARS-CoV-2 in the GI tract and infectious virus has occasionally been recovered from both urine and stool samples. The level and infectious capability of SARS-CoV-2 in vomit remain unknown. In comparison to enteric viruses transmitted via the fecal-oral route (e.g. norovirus, adenovirus), the likelihood of SARS-CoV-2 being transmitted via feces or urine appears lower due to the lower relative amounts of virus present in feces/urine. The biggest risk of transmission will occur in clinical and care home settings where secondary handling of people and urine/fecal matter occurs. In addition, while SARS-CoV-2 RNA genetic material can be detected by in wastewater, this signal is greatly reduced by conventional treatment. Our analysis also suggests the likelihood of infection due to contact with sewage-contaminated water (e.g. swimming, surfing, angling) or food (e.g. salads, shellfish) is extremely low or negligible based on very low predicted abundances and limited environmental survival of SARS-CoV-2. These conclusions are corroborated by the fact that over eight million global cases of COVID-19 have occurred, but exposure to feces or wastewater has never been implicated as a transmission vector.
Sun, 19 July 2020
ARTICLE | doi:10.20944/preprints202007.0410.v1
Subject: Life Sciences, Virology Keywords: Chikungunya virus; invasion; transmission dynamics; Aedes aegypti; Aedes albopictus; mathematical model
Online: 19 July 2020 (14:40:22 CEST)
: Arboviruses transmitted by Aedes aegypti and Ae. albopictus have been introduced to Florida on many occasions. Infrequently, these introductions lead to sporadic local transmission and, more rarely, sustained local transmission. Both mosquito species are present in Florida, with spatio-temporal variation in population composition. We developed a 2-vector compartmental, deterministic model to investigate factors influencing Chikungunya virus (CHIKV) establishment. The model includes a non-linear, temperature-dependent mosquito mortality function based on minimum mortality in a central temperature region. Latin Hypercube sampling was used to generate parameter sets used to simulate transmission dynamics, following the introduction of one infected human. The analysis was repeated for 3 values of the mortality function central temperature. Mean annual temperature was consistently important in the likelihood of epidemics, and epidemics increased as the central temperature increased. Ae. albopictus recruitment was influential at the lowest central temperature while Ae. aegypti recruitment was influential at higher central temperatures. Our results indicate that the likelihood of CHIKV establishment may vary, but overall Florida is permissive for introductions. Model outcomes were sensitive to the specifics of mosquito mortality. Mosquito biology parameters are variable, and improved understanding of this variation will improve our ability to predict the outcome of introductions.
Fri, 17 July 2020
CASE REPORT | doi:10.20944/preprints202007.0398.v1
Online: 17 July 2020 (16:02:28 CEST)
The pandemic respiratory disease COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in Wuhan in December 2019 and then spread throughout the world; Italy was the most affected European country. Despite the close pet-human contact, little is known about the predisposition of pets to SARS-CoV-2. Among these, felines are the most susceptible. In this study, a domestic cat with clear symptoms of pneumonia, confirmed by Rx imaging, was found to be infected by SARS-CoV-2 using quantitative RT–qPCR from a nasal swab. This is the first Italian study reporting on the request of the scientific community to focus attention on the possible role of pets as a SARS-CoV-2 reservoir. An important question remains unanswered: did the cat die from SARS-CoV-2 infection?
ARTICLE | doi:10.20944/preprints202007.0363.v1
Subject: Life Sciences, Virology Keywords: Ebola virus; filovirus; lipid binding; matrix protein; VP24
Online: 17 July 2020 (06:00:08 CEST)
Viral protein 24 (VP24) from Ebola virus (EBOV) was first recognized as a minor matrix protein that associates with cellular membranes. However, more recent studies shed light on its roles in inhibiting viral genome transcription and replication, facilitating nucleocapsid assembly and transport, and interfering with immune responses in host cells through downregulation of interferon (IFN)-activated genes. Thus, whether VP24 is a peripheral protein with lipid binding ability for matrix layer recruitment has not been explored. Here we examined the lipid binding ability of VP24 with a number of lipid binding assays. The results indicated that VP24 lacked the ability to associate with lipids tested regardless of VP24 posttranslational modifications. We further demonstrate that the presence of the EBOV major matrix protein VP40 did not promote VP24 membrane association in vitro or in cells. Further, no protein-protein interactions between VP24 and VP40 were detected by co-immunoprecipitation. Confocal imaging and cellular membrane fractionation analyses in human cells suggested VP24 did not specifically localize at the plasma membrane inner leaflet. Overall, we provide evidence that EBOV VP24 is not a lipid binding protein and its presence in the viral matrix layer is likely not dependent on direct lipid interactions.
Thu, 16 July 2020
Subject: Life Sciences, Virology Keywords: COVID-19; low-virulence; high-virulence; pandemic; T-cell; immunity; virus; SARS-CoV-2
Online: 16 July 2020 (13:02:40 CEST)
Abstract The COVID-19 pandemic is thought to began in Wuhan, China in December 2019. Mobility analysis identified East-Asia and Oceania countries to be highly-exposed to COVID-19 spread, consistent with the earliest spread occurring in these regions. However, here we show that while a strong positive correlation between case-numbers and exposure level could be seen early-on as expected, at later times the infection-level is found to be negatively correlated with exposure-level. Moreover, the infection level is positively correlated with the population size, which is puzzling since it has not reached the level necessary for population-size to affect infection-level through herd immunity. These issues are resolved if a low-virulence Corona-strain (LVS) began spreading earlier in China outside of Wuhan, and later globally, providing immunity from the later appearing high-virulence strain (HVS). Following its spread into Wuhan, cumulative mutations gave rise to the emergence of an HVS, known as SARS-CoV-2, starting the COVID-19 pandemic. We model the co-infection by an LVS and an HVS, and show that it can explain the evolution of the COVID-19 pandemic and the non-trivial dependence on the exposure level to China and the population-size in each country. We find that the LVS began its spread a few months before the onset of the HVS, and that its spread doubling-time is times slower than the HVS. Although more slowly spreading, its earlier onset allowed the LVS to spread globally before the emergence of the HVS. In particular, in countries exposed earlier to the LVS and/or having smaller population-size, the LVS could achieve herd-immunity earlier, and quench the later-spread HVS at earlier stages. We find our two-parameter (the spread-rate and the initial onset time of the LVS) can accurately explain the current infection levels (R^2; correlation p-value (p) of 5x10^-13). Furthermore, countries exposed early should have already achieved herd-immunity. We predict that in those countries cumulative infection levels could rise by no more than 2-3 times the current level through local-outbreaks, even in the absence of any containment measures. We suggest several tests and predictions to further verify the double-strain co-infection model and discuss the implications of identifying the LVS.
Wed, 15 July 2020
Subject: Life Sciences, Virology Keywords: epidemic; caseload management; partial unlock; social distancing; overshoot; COVID-19; coronavirus; economic impact; ventilator utilization; SARS-CoV-2
Online: 15 July 2020 (03:14:33 CEST)
Background: A large percentage of deaths in an epidemic or pandemic can be due to overshoot of population (herd) immunity, either from the initial peak or from planned or unplanned exit from lockdown or social distancing conditions. Objectives: We study partial unlock or reopening interaction with seasonal effects in a managed epidemic to quantify overshoot effects on small and large unlock steps and discover robust strategies for reducing overshoot. Methods: We simulate partial unlock of social distancing for epidemics over a range of replication factor, immunity duration and seasonality factor for strategies targeting immunity thresholds using overshoot optimization. Results: Seasonality change must be taken into account as one of the steps in an easing sequence, and a two step unlock, including seasonal effects, minimizes overshoot and deaths. It may cause undershoot, which causes rebounds and assists survival of the pathogen. Conclusions: Partial easing levels, even low levels for economic relief while waiting on a vaccine, have population immunity thresholds based on the reduced replication rates and may experience overshoot as well. We further find a two step strategy remains highly sensitive to variations in case ratio, replication factor, seasonality and timing. We demonstrate a three or more step strategy is more robust, and conclude that the best possible approach minimizes deaths under a range of likely actual conditions which include public response.
Thu, 9 July 2020
REVIEW | doi:10.20944/preprints202007.0194.v1
Subject: Life Sciences, Virology Keywords: COVID19; Airborne transmission; Droplet transmission; Aerosol transmission; SARS-CoV-2; Heat Inactivation; Infection Prevention; Ventilation system
Online: 9 July 2020 (12:32:42 CEST)
Coronavirus disease 2019 (COVID-19), caused by the novel coronavirus SARS-CoV-2, has been confirmed in over 10,000,000 individuals worldwide and has resulted in more than 500,000 deaths in a few months since it first surfaced. With such a rapid spread it is no surprise that there has been a massive effort around the world to collectively elucidate the mechanism by which the virus is transmitted. Despite this, there is still no definitive consensus regarding droplet versus airborne transmission of SARS-CoV-2. Public health officials around the world have introduced guidelines within the scope of droplet transmission. However, increasing evidence and comparative analysis with similar coronaviruses, such as severe acute respiratory syndrome (SARS-CoV-1) and middle eastern respiratory syndrome (MERS), suggest that airborne transmission of SARS-CoV-2 cannot be effectively ruled out. As the data supporting COVID-19 airborne transmission grows, there needs to be an increased effort in terms of technical and policy measures to mitigate the spread of viral aerosols. These measures can be in the form of broader social distancing and facial covering guidelines, exploration of thermal inactivation in clinical settings, low-dose UV-C light implementation, and greater attention to ventilation and airflow control systems. This review summarizes the current evidence available about airborne transmission of SARS-CoV-2, available literature about airborne transmission of similar viruses, and finally the methods that are already available or can be easily adapted to deal with a virus capable of airborne transmission.
Wed, 8 July 2020
COMMUNICATION | doi:10.20944/preprints202007.0159.v1
Subject: Life Sciences, Virology Keywords: COVID-19; herd immunity; pandemic; pathogenesis; SARS-CoV-2; WHO
Online: 8 July 2020 (18:33:41 CEST)
Herd immunity happens when a relatively large proportion of a population becomes infected by an agent, subsequently recovers, and attains immunity against the same agent. That proportion thus indirectly protects the naïve population by preventing the spread of the infection. Herd immunity has been suggested to interrupt and control the COVID-19 pandemic. However, relying on establishing herd immunity can be catastrophic considering the virulence and lethality of SARS-CoV-2. Meanwhile our understanding of the pathogenesis, case-fatality rate, transmission routes, and antiviral therapy for COVID-19 remains limited now. Interrupting or slowing the COVID-19 transmission seems more opportune than vaccination, antiviral therapy, or herd immunity, all of which will take some time to yield. Thus, social distancing, face-masking, and hygiene are the most appropriate immediate countermeasures. Because the social fabrics, economic implications, and local demands of various nations are unique, early relaxation of restrictions may seem hasty particularly when fatality rates are high, or when the healthcare systems could be inadequate or become inundated. Conclusively, avoiding any overwhelmingly risky approach in fighting the pandemic is prudent.
ARTICLE | doi:10.20944/preprints202007.0144.v1
Subject: Life Sciences, Virology Keywords: phylodynamic analyses; SARS-CoV2 circulation in Italy; molecular tracing; Whole Genome Sequencing
Online: 8 July 2020 (11:00:19 CEST)
The aim of this study is the characterization and genomic tracing by phylogenetic analyses of 59 new SARS-CoV-2 Italian isolates obtained from patients attending clinical centres in North and Central Italy until the end of April 2020. All but one of the newly characterized genomes belonged to the lineage B.1, the most frequently identified in European countries, including Italy. Only a single sequence was found to belong to lineage B. A mean of 6 nucleotide substitutions per viral genome was observed, without significant differences between synonymous and non-synonymous mutations, indicating genetic drift as a major source for virus evolution. tMRCA estimation confirmed the probable origin of the epidemic between the end of January and the beginning of February with a rapid increase in the number of infections between the end of February and mid-March. Since early February, an effective reproduction number (Re) greater than 1 was estimated, which then increased reaching the peak of 2.3 in early March, confirming the circulation of the virus before the first COVID-19 cases were documented. Continuous use of state-of-the-art methods for molecular surveillance is warranted to trace virus circulation and evolution and inform effective prevention and containment of future SARS-CoV-2 outbreaks.
Tue, 7 July 2020
ARTICLE | doi:10.20944/preprints202007.0105.v1
Subject: Life Sciences, Virology Keywords: Zika virus; yellow fever virus; cross-reactivity; neutralization; enhancement; zika congenital syndrome; stem cells
Online: 7 July 2020 (02:29:39 CEST)
Zika virus (ZIKV) is a flavivirus that originated in Africa but emerged in Latin America in 2015. In this region, other flaviviruses such as Dengue (DENV), West Nile, and Yellow Fever Virus (YFV) also circulate, allowing for possible antigenic cross-reactivity to impact viral infections and immune responses. Studies have found antibody mediated enhancement between DENV and ZIKV, but the impact of YFV antibodies on ZIKV infection has not been fully explored. ZIKV infections cause congenital syndromes, such as microcephaly, necessitating further research into ZIKV vertical transmission through the placental barrier. Recent advancements in biomedical engineering have generated co-culture methods that allow for in vitro recapitulation of the maternal: fetal interface. This study utilized a transwell assay, which is a co-culture model utilizing human placental syncytiotrophoblasts, fetal umbilical cells, and a differentiating embryoid body to replicate the maternal: fetal axis. To determine if cross reactive YFV vaccine antibodies impact the pathogenesis of ZIKV across the maternal fetal axis, maternal syncytiotrophoblasts were inoculated with ZIKV or ZIKV incubated with YFV vaccine anti-sera, and viral load was measured 72 hours post inoculation. Here we report that BeWo and HUVEC cells are permissive to ZIKV and that the impact of YFV post-vaccination antibodies on ZIKV replication is cell line dependent. Embryoid bodies are also permissive to ZIKV and the presence of YFV antibodies collected 1 to 6 months post vaccination enhances ZIKV infection. Our data show that each of the cell lines and EBs have a unique response to ZIKV complexed with post-vaccination serum suggesting there may be cell-specific mechanisms that impact congenital ZIKV infections. Since ZIKV infections can cause severe congenital syndromes, it is crucial to understand any potential enhancement or protection offered from cross-reactive, post-vaccination antibodies.
Mon, 6 July 2020
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; ambient temperature; risk level; mortality
Online: 6 July 2020 (10:25:09 CEST)
COVID-19 is a pandemic with no cure. There is an urgent need for low-cost interventions. Macroclimate work through affecting microclimate. In many situations, man-made microclimate, such as air conditioning, may override the effect of natural macroclimate in determining SARS-CoV-2 pathogenicity. Ambient temperature (AT) has been roughly associated to SARS-CoV-2 transmission. To translate into a feasible practice in controlling COVID-19 pandemic, in-depth and implementable knowledge of AT role in SARS-CoV-2 transmission should be unveiled. This study aimed to determine if there is a ‘safe’ temperature that is comfortable to human beings while significantly inhibitory for SARS-CoV-2 pathogenicity. Data on monthly new deaths or new cases per million population (MDPM or MCPM) and monthly cumulated days with more cases than the previous day (DI) from March 2 to June 30, 2020 were collected from all 118 countries with population over five million. Monthly average AT negatively correlated with the transmission parameters. A significant decrease in transmission was observed when AT reached above 20 ºC. Monthly average (not average high) AT of countries with MDPM <2, MCPM<10, or DI<=7 was found to be between 24.54 and 26.89 ºC (25.18 ºC on average) with average standard error of 4.81. Thus, average AT <20, 20-25, >25 ºC were considered as high, medium, and low risk AT. Furthermore, MDPM in countries with AT <20 ºC were 80.93, 50.23, 13.52, and 5.05 times of those in countries with AT >25 ºC in March, April, May, and June, respectively. MDPM low-risk rates (<2) in countries with AT >25 ºC were 100, 83.33, 52.73, and 52.46%, respectively. In countries with AT <20 ºC, the trends were opposite. Setting indoor temperature to 25 ºC could decrease the need of social distancing for containing SARS-CoV-2 transmission. Ventilation and sanitizing the air with ultraviolet light in nonbusiness hours may be additionally effective. Cooling indoor temperature too low may be a reason of COVID-19 outbreak in some high AT countries. Authorities and the general population can evaluate COVID-19 risk level and manipulate microclimate to reduce the risk anywhere anytime based on local day average AT.
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; Quinine; Hydroxy-Chloroquine; Chloroquine; COVID-19; antiviral
Online: 6 July 2020 (09:19:06 CEST)
Since there is no vaccine or regulatory approved therapy available for treatment of SARS-CoV-2 infection, the medical need to prevent the transition of a mild into the severe COVID-19 stage of infection is of outmost importance. Among several drug candidates, Chloroquine (CQN) and Hydroxy-Chloroquine (H-CQN) have been tested most intensively. However, the therapeutic effect of H-CQN and CQN has been discussed controversially in the light of severe side effects. Originally, H-CQN descended from the natural substance Quinine, a medicinal product used since the Middle Ages and is now regulatory approved for various indications. We hypothesized that Quinine also exerts anti-SARS-CoV-2 activity. First, virus production in Vero B4 cells was analyzed by Western blot, showing that Quinine exerts antiviral activity against SARS-CoV-2 that at 10 µM was even stronger than that of H-CQN or CQN. Second, fluorescence end-point and time lapse analysis of SARS-CoV-2-mNeonGreen-infected Caco-2 cells could confirm a similar antiviral effect of Quinine in a human-derived cell line. Thereby, our in vitro studies revealed, that the antiviral effect appears to be specific, since in Vero cells Quinine impacted cell viability at approximately 50-fold higher concentration, while the therapeutic window of H-CQN and CQN was approximately 10-fold lower. In Caco-2 cells no toxic effect was observed while complete block of infection occurred between 50 and 100 µM at high MOIs. In conclusion, our data indicate that Quinine would have the potential of a well tolerable and widely used treatment option for SARS-CoV-2 infections, with a predictable and significantly better toxicological profile when compared to H-CQN or CQN.
Sun, 5 July 2020
ARTICLE | doi:10.20944/preprints202007.0049.v1
Subject: Life Sciences, Virology Keywords: Sars-CoV-2; proteome; mutation; ORF3a; Nucleoprotein; Nsp2
Online: 5 July 2020 (06:54:01 CEST)
The Sars-CoV-2 is the causative agent of the current coronavirus disease pandemic. To effectively fight this pathogen, it is important to understand its evolution and the mechanism of adaptation to the host. A software workflow has been utilized to scan 26,016 Sars-CoV-2 genomes available in GISAID databank to analyse the distribution and frequency of mutations in the corresponding proteomes. A filtering procedure has been applied to remove data inconsistencies and redundancies. The number of observed mutations appears proportional to protein sequence length except for ORF3a, Nucleocapsid and Nsp2 that seem to accept more mutations than expected. The most pervasive mutations of the three proteins have been reported and the most variable and conservative regions mapped onto the respective sequences. The results suggest that these proteins may have a role in the adaptation of virus to new hosts and influence its pathogenicity and replication. These considerations prompt the experimental study and characterization of the three proteins.
Fri, 3 July 2020
Online: 3 July 2020 (09:45:43 CEST)
The novel respiratory disease COVID-19 has reached the status of worldwide pandemic and large efforts are currently being undertaken in molecularly characterizing the virus causing it, SARS-CoV-2. The genomic variability of SARS-CoV-2 specimens scattered across the globe can underly geographically specific etiological effects. In the present study, we gather the 48,635 SARS-CoV-2 complete genomes currently available thanks to the collection endeavor of the GISAID consortium and thousands of contributing laboratories. We analyze and annotate all SARS-CoV-2 mutations compared with the reference Wuhan genome NC_045512.2, observing an average of 7.23 mutations per sample. Our analysis shows the prevalence of single nucleotide transitions as the major mutational type across the world. There exist at least three clades characterized by geographic and genomic specificity. In particular, the clade G, prevalent in Europe, carries a D614G mutation in the Spike protein, which is responsible for the initial interaction of the virus with the host human cell. Our analysis may drive local modulation of antiviral strategies based on the molecular specificities of this novel virus.
Tue, 30 June 2020
ARTICLE | doi:10.20944/preprints202006.0373.v1
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; ambient temperature; risk level; mortality
Online: 30 June 2020 (13:10:27 CEST)
COVID-19 is a pandemic with no cure. There is an urgent need for low-cost interventions. Macroclimate work through microclimate. In many situations, man-made microclimate, such as air conditioning, may override the effect of natural macroclimate in determining the pathogenicity of SARS-CoV-2. This study aimed to determine if there is a ‘safe’ temperature that is comfortable to human beings while significantly inhibitory for SARS-CoV-2 pathogenicity. Data on monthly new deaths or new cases per million population (MDPM or MCPM) and monthly cumulated days with more cases than the previous day (DI) from March 2 to June 15, 2020 were collected from all 118 countries with population over five million. Monthly average AT negatively correlated with the transmission parameters. A significant decrease in transmission was observed when AT reached above 20 ºC. Monthly average (not average high) AT of countries with MDPM <2, MCPM<10, or DI<=7 was found to be between 24.54 and 25.90 ºC (25.00 ºC on average) with average standard error of 4.97. Thus, average AT <20, 20-25, >25 ºC were considered as high, medium, and low risk AT. Furthermore, MDPM in countries with AT <20 ºC were 80.93, 50.23, 13.52, and 7.72 times of those in countries with AT >25 ºC in March, April, May, and June 1-15, respectively. MDPM high-risk rates in countries with AT >25 ºC were 0, 6.25, 14.55, and 9.84%, and the low-risk rates were 100, 83.33, 52.73, and 81.97%, respectively. In countries with AT <20 ºC, the trends were opposite. Setting indoor temperature to 25 ºC could decrease the need of social distancing for containing SARS-CoV-2 transmission. Cooling indoor temperature too low may be a reason of COVID-19 outbreak in some high AT countries. Authorities and the general population can evaluate COVID-19 risk level and manipulate microclimate to reduce the risk anywhere anytime based on local day average AT.
Mon, 29 June 2020
ARTICLE | doi:10.20944/preprints202006.0352.v1
Online: 29 June 2020 (10:40:07 CEST)
Mitochondria are classically termed as powerhouse of a mammalian cell. Most of the cellular chemical energy in the form of adenosine tri phosphate (ATP) is generated by mitochondria and dysregulation of mitochondrial functions thus can be potentially fatal of cellular homeostasis and health. Acute respiratory distress has been earlier linked to mitochondrial dysfunction. SARS-CoV-2 infection severity leads to acute respiratory distress syndrome (ARDS) and can be fatal. We tried to investigate possible connection between SARS-CoV-2, ARDS and mitochondria. Here, we report identification of SARS-CoV-2 non-structural proteins (particularly Nsp12 and 13) that have recognition sequence with respect to mitochondrial entry. We also report that these proteins can potentially shuttle between cytoplasm and mitochondria based on the localization signals and help in downstream maintenance of the virus. Their properties to use ATP for enzymatic activities may cause ATP scavenging allowing viral RNA functions in lieu of host cell health.
Sun, 28 June 2020
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; novel severe acute respiratory syndrome coronavirus 2; ancestral reconstruction; clonality; source of entry; dispersal routes
Online: 28 June 2020 (09:21:49 CEST)
The coronavirus disease 2019 (COVID-19) was officially declared a pandemic on the 11th March 2020. It is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), impacting the lower respiratory tract. International travel to Australia during the early stages of the pandemic prior to border closure provided avenues for this virus to spread into Australia. There is little understanding of the clonality of SARS-CoV-2 isolates in Australia, and where they originated. This study aimed to investigate the clonality and ancestral sources of SARS-CoV-2 isolates in Australia using in silico methods. We retrieved 1,346 complete genomes from Australia along with 153 genomes from other countries from the NCBI nucleotide database and Global Initiative On Sharing All Influenza Data (GISAID). We then constructed a representative population of 270 sequences for downstream phylogenetic analysis and ancestral area reconstruction. Overall, two major clusters, one stemming from Europe and another from Asia, especially East Asia, were observed, implying at least two major transmission events with subsequent clades confirming the multiclonality of Australian isolates. We also identified three potential dissemination routes of SARS-CoV-2 into Australia. This study supports the hypothesis of multiple clonality and dispersals of SARS-CoV-2 isolates into Australia.
Thu, 18 June 2020
REVIEW | doi:10.20944/preprints202006.0216.v2
Subject: Life Sciences, Virology Keywords: SARS-coronavirus; Severe Acute Respiratory Syndrome; COVID-19; Stool; Urine; Wastewater; Wastewater-based epidemiology
Online: 18 June 2020 (09:29:00 CEST)
The COVID-19 pandemic has revealed many knowledge gaps with implications toward the speed and nature of our response to contain, assess and mitigate risk. The routine discharge of treated and untreated wastewater into rivers and coastal waters has placed SARS-CoV-2 viability in wastewater at the centre of an emerging hazard and potential risk to water industry workers and the public who come into contact with sewage-impacted water. Here we provide a review of the Severe Acute Respiratory Syndrome coronavirus primary literature that presents the evidence base pertaining to the key questions of whether the SARS-CoV-1 and SARS-CoV-2 is shed in stool and urine, is recoverable, and infectious in wastewater. We discuss the challenges posed by the current literature base and the extent to which the current evidence is fit for the purpose of informing robust human and environmental risk assessments.
SHORT NOTE | doi:10.20944/preprints202006.0225.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; web application; virus genome; lineage assignment; amino acids
Online: 18 June 2020 (06:24:20 CEST)
Summary CoV-GLUE is an online web application for the interpretation and analysis of SARS-CoV-2 virus genome sequences, with a focus on amino acid sequence variation. It is based on the GLUE data-centric bioinformatics environment and provides a browsable database of amino acid replacements and coding region indels that have been observed in sequences from the pandemic. Users may also analyse their own SARS-CoV-2 sequences by submitting them to the web application to receive an interactive report containing visualisations of phylogenetic classification and highlighting genomic variation of potentially high impact, for example linked to primer mismatches.Availability and implementation Available at http://cov-glue.cvr.gla.ac.uk. Implemented using GLUE, an open source framework for the development of virus sequence data resources. Contact [email protected]
ARTICLE | doi:10.20944/preprints202005.0505.v2
Subject: Life Sciences, Virology Keywords: COVID-19; Viral Co-infection; SARS-CoV-2; Influenza A virus; Human Immunodeficiency virus
Online: 18 June 2020 (04:57:14 CEST)
In December 2019, pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection emerged in Wuhan City, Hubei Province, China. Early in 2020, the World Health Organization (WHO) announced a new name for the 2019-nCoV-caused epidemic disease: coronavirus disease 2019 (COVID-19) and declared COVID-19 to be the sixth international public health emergency. Cellular co-infection is a critical determinant of both viral fitness and infection outcome and plays a crucial role in shaping the host immune response to infections. In this study, sixty-eight public next-generation sequencing libraries from SARS-CoV-2 infected patients were retrieved from the NCBI Sequence Read Archive database using SRA-Toolkit. Using an alignment-free method based on K-mer mapping and extension, SARS-CoV-2 was identified in all except three patients. Influenza A H7N9 (3/68), Human immunodeficiency virus 1 (1/68), rhabdovirus isolate (3/68), Human metapneumovirus (1/68), coronaviruses NL63 (1/68), Parvovirus (1/68), Simian virus 40 (1/68), and hepatitis virus (1/68) genome sequences were detected in SARS-CoV-2 infected patients.
Wed, 17 June 2020
REVIEW | doi:10.20944/preprints202006.0216.v1
Subject: Life Sciences, Virology Keywords: SARS; Severe Acute Respiratory Syndrome; COVID-19; Stool; Urine; Wastewater; Wastewater-based epidemiology
Online: 17 June 2020 (13:09:06 CEST)
The COVID-19 pandemic has revealed many knowledge gaps with implications toward the speed and nature of our response to contain, assess risk, and mitigate. The routine discharge of treated and untreated wastewater into rivers and coastal waters has placed SARS-CoV-2 viability in wastewater at the centre of an emerging hazard and potential risk to water industry workers and the public who come into contact with sewage-impacted water. Here we provide a review of the SARS-CoV-1 and SARS-CoV-2 primary literature that presents the evidence base pertaining to the key questions of whether the virus is shed in stool and urine, is recoverable, and infectious in wastewater and sludge. We discuss the challenges posed by the current literature base and the extent to which the current evidence is fit for the purpose of informing robust human and environmental risk assessments.
Sun, 14 June 2020
REVIEW | doi:10.20944/preprints202006.0086.v2
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; Genome organisation and expression; Polyproteins; Prevention strategies
Online: 14 June 2020 (16:49:10 CEST)
COVID-19 manifests regarding extreme acute respiratory conditions caused by a novel beta coronavirus (SARS-CoV-2) which is reported to be the seventh coronavirus to infect humans. Like other SARS-CoVs it has a large positive-stranded RNA genome. But specific furin site in the spike protein, mutation prone and phylogenetically mess Orf1ab separates SARS-CoV-2 from other RNA viruses. Since, the outbreak (February - March 2020) which originated in China, researchers, scientists, and medical professionals are inspecting all possible facts from every possible aspect including its replication, detection, and prevention strategies. This led to the prompt identification of its basic biology, genome characterization, structural based functional information of proteins, and strategies to prevent its spread. Due to the rapid mutation rate, the functional characterization of a few proteins is still lagging. This review summarizes the recent updates on the basic molecular biology of SARS-CoV-2 and prevention strategies undertaken worldwide to tackle COVID-19. This recent information can be implemented for the development and designing of therapeutics against SARS-CoV-2.
ARTICLE | doi:10.20944/preprints202006.0176.v1
Subject: Life Sciences, Virology Keywords: Simple Sequence Repeats; Polyomaviridae; Prevalence, Distribution; Virus Host; Evolution
Online: 14 June 2020 (14:35:24 CEST)
The simple sequence repeats (SSRs) are small 1-6bp tandem repeat elements present across diverse genomes and involved in gene regulation and evolution. Presently we analyzed SSRs in genomes of 98 species of family Polyomaviridae across four genera. The genome size ranged from 3962bp (BM87) to 7369bp (BM85) but maximum genomes were in the range of 5 to 5.5 kb. The GC% had an average of 42% and ranged between 34.69 (BM95) to 52.35 (BM81). A total of 3036 SSRs and 223 cSSRs were extracted using IMEx with incident frequency from 18 to 56 and 0 to 7 respectively. The most prevalent mono-nucleotide repeat motif was “T” (48.95%) followed by “A” (33.48%). “AT/TA” was the most prevalent dinucleotide motif closely followed by “CT/TC”. The distribution was expectedly more in coding region with 77.6% SSRs of which nearly half were in Large T Antigen (LTA) gene. Notably, most viruses with humans, apes and related species as host exhibited exclusivity of mono-nucleotide repeats in AT region, a proposed predictive marker for determination of humans as host in virus in course of its evolution. Each genome has a unique SSR signature which is pivotal for viral evolution particularly in terms of host divergence.
ARTICLE | doi:10.20944/preprints202006.0165.v1
Subject: Life Sciences, Virology Keywords: conserved signature indels specific for SARS and SARS-CoV-2 viruses; DNA and Protein markers distinguishing different clades of Sarbecoviruses; evolutionary origin of SARS and SARS-CoV-2 viruses
Online: 14 June 2020 (04:09:39 CEST)
Both SARS-CoV-2 (COVID-19) and SARS coronaviruses (CoVs) are members of the subgenus Sarbecovirus. To understand the origin of SARS-CoV-2 and its relation to other viruses, protein sequences from sarbecoviruses were analyzed to identify conserved inserts or deletions (termed CSIs) demarcating either particular clusters/lineages of sarbecoviruses or those shared by specific lineages shedding light on their interrelationships. We report several clade-specific CSIs in the spike (S) and nucleocapsid (N) proteins that reliably demarcate distinct sarbecoviruses clades providing important insights into the origin and evolution of SARS-CoV-2. Two CSIs in the N-terminal domain (NTD) of S-protein are uniquely shared by SARS-CoV-2, BatCoV-RaTG13 and most pangolin CoVs (SARS-CoV-2r cluster); another CSI supports a closer relationship of SARS-CoV-2 to BatCov-RaTG13. Three additional CSIs in the NTD are specific for two Bat-SARS-like CoVs (viz. CoVZXC21 and CoVZC45; CoVZC cluster) which form an outgroup of the SARS-CoV-2r cluster. Interestingly, one of the pangolin-CoV-MP789 also shares these CSIs but lack the CSIs specific for the SARS-CoV-2r cluster. The N-terminal sequence (aa 1-320) of the S-protein for pangolin-CoV-MP789 shows highest similarity (85.94%) to the CoVZC cluster, while its C-terminal region including the receptor binding domain (RBD) is most similar (97-98% identity) to the SARS-CoV-2 virus. These observations indicate that the spike protein sequence for the strain MP789 is of chimeric origin. Multiple CSIs described here also distinguish two bat SARS-CoVs strains (BM48-31/BGR/2008 and SARS_BtKY72) from all others. Our work also clarifies that two large CSIs (5 aa and 13 aa) found in the RBD of S-protein are mainly specific for the SARS and SARS-CoV-2r clusters of CoVs. The surface loops formed by these CSIs are predicted to be important in the binding of S-protein with the human ACE-2 receptor. Lastly, we have mapped the locations of different CSIs in the structure of the S-protein. These studies reveal that the three CSIs specific for the SARS-CoV-2r cluster form distinct surface-exposed loops/patches on the S-protein. As the surface-exposed loops play important roles in mediating novel interactions, the novel lobes/patches formed by the SARS-CoV-2-specific CSIs in the spike protein are predicted to play important roles in the interaction of this protein with other surface-exposed components in the host cells thereby enhancing the binding/infectivity of this virus to humans.
Fri, 12 June 2020
REVIEW | doi:10.20944/preprints202006.0145.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; Exosome; Extracellular Vesicle; Diagnostics; Vaccine; Treatment
Online: 12 June 2020 (09:01:02 CEST)
Our first modern global pandemic is caused by a nanosized lipid vesicle, called SARS-CoV-2. Its molecular structure and biogenesis have remarkable similarities with Extracellular Vesicles (EVs, most notably exosomes) that are constantly shed by all cells during their life. Their resemblance may not be a coincidence. Growing body of evidence has shown that EVs have significant roles in various biological processes, including viral infection, transmission and anti-viral response. Drawing comparison with the virus might shed light on how we could fight the COVID-19 disease. This may include novel EV research and diagnostics technologies as well as novel EV-based treatments.
Sun, 7 June 2020
REVIEW | doi:10.20944/preprints202006.0086.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; Genome organisation and expression; Polyproteins; Prevention strategies
Online: 7 June 2020 (11:57:52 CEST)
COVID-19 manifests regarding extreme acute respiratory conditions caused by a novel beta coronavirus (SARS-CoV-2) which is reported to be the seventh coronavirus to infect humans. Like other SARS-CoVs it has a large positive-stranded RNA genome. But specific furin site in the spike protein, mutation prone and phylogenetically mess Orf1ab separates SARS-CoV-2 from other RNA viruses. Since, the outbreak (February - March 2020) which originated in China, researchers, scientists, and medical professionals are inspecting all possible facts from every possible aspects including its replication, detection and prevention strategies. This led to the prompt identification of its basic biology, genome characterization, structural based functional information of proteins and strategies to prevent its spread. Due to rapid mutation rate, functional characterization of few proteins is still lagging. This review summarizes the recent updates on basic molecular biology of SARS-CoV-2 and prevention strategies undertaken worldwide to tackle COVID-19. This recent information can be implemented for the development and designing of therapeutics against SARS-CoV-2.
ARTICLE | doi:10.20944/preprints202006.0073.v1
Subject: Life Sciences, Virology Keywords: Epidemiology; SARS-CoV-2; Multivariable regression; Tuberculosis; Demography; Coronavirus; MMR vaccine
Online: 7 June 2020 (09:25:55 CEST)
COVID-19 pandemic that started in China has spread within 3 months to the entire globe. We tested the hypothesis that the vaccination against tuberculosis by BCG correlates with a better outcome for COVID-19 patients. Our analysis covers 55 countries complying with predetermined thresholds on the population size and number of deaths per million (DPM). We found a strong negative correlation between the years of BCG administration and the DPM along with the progress of the pandemic, corroborated by permutation tests. The results from multivariable regression tests with 23 economic, demographic, health-related, and pandemic restriction quantitative properties, substantiate the dominant contribution of BCG years to the COVID-19 outcomes. The analysis of countries according to an age-group partition reveals that the strongest correlation is attributed to the coverage in BCG vaccination of the young population (0-24 years). Furthermore, a strong correlation and statistical significance are associated with the degree of BCG coverage for the most recent 15 years, but no association was observed in these years for other broadly used vaccination protocols for measles and rubella. We propose that BCG immunization coverage, especially among the most recently vaccinated contributes to attenuation of the spread and severity of the COVID-19 pandemic.
Sun, 31 May 2020
BRIEF REPORT | doi:10.20944/preprints202005.0515.v1
Subject: Life Sciences, Virology Keywords: Covid-19; Herd Immunity Threshold; Corona Virus; Innate immunity; flattening the curve; serological survey
Online: 31 May 2020 (21:14:05 CEST)
We have analysed the death and recovery rate of Covid-19 disease progression. From the analysis, we have argued that the pandemic is over in certain countries (labelled as group-A) and for other countries (labelled as group-B) the disease appears to remain as endemic. Taking into account the serological survey (sero-survey) test results obtained by certain groups and comparing it with herd immunity threshold value one can infer that the low number of infection for group-B is either due to acquired immunity by some previous infection by other coronavirus or due to innate immunity towards this infection. This effect is stronger for group-B to slow the progress of the disease to such an extent resulting in flattening of the disease progression curve compared to group-A.
ARTICLE | doi:10.20944/preprints202005.0505.v1
Subject: Life Sciences, Virology Keywords: COVID-19; Viral Co-infection; SARS-CoV-2; Influenza A virus; Human Immunodeficiency virus
Online: 31 May 2020 (20:36:28 CEST)
In December 2019, pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection emerged in Wuhan City, Hubei Province, China. Early in 2020, the World Health Organization (WHO) announced a new name for the 2019-nCoV-caused epidemic disease: coronavirus disease 2019 (COVID-19) and declared COVID-19 to be the sixth international public health emergency. Cellular co-infection is a critical determinant of both viral fitness and infection outcome and plays a crucial role in shaping the host immune response to infections. In this study, sixty-eight public next-generation sequencing libraries from SARS-CoV-2 infected patients were retrieved from the NCBI Sequence Read Archive database using SRA-Toolkit. Using an alignment-free method based on K-mer mapping and extension, SARS-CoV-2 was identified in all except three patients. Influenza A H7N9 (3/68), Human immunodeficiency virus 1 (1/68), Spodoptera frugiperda rhabdovirus isolate (3/68), Human metapneumovirus (1/68), coronaviruses NL63 (1/68), Sri Lankan cassava mosaic virus (1/68), Indian cassava mosaic virus (1/68), Parvovirus (1/68), Simian virus 40 (1/68), Woodchuck hepatitis virus (1/68), Saccharomyces 20S RNA narnavirus (2/68), and Autographa californica nucleopolyhedrovirus (2/68) genome sequences were detected in SARS-CoV-2 infected patients.
HYPOTHESIS | doi:10.20944/preprints202005.0480.v1
Subject: Life Sciences, Virology Keywords: endothelial; infection; basement membrane; fibroblast; fibrosis; nsp7; hypothesis; pathogenesis; COVID-19; SARS-CoV2
Online: 31 May 2020 (16:28:19 CEST)
Severe COVID-19 is associated with viraemia and multiple organ disease. Similar clinicopathological features have been previously seen in SARS and MERS. Clinically, the severity of SARS, MERS and COVID-19 has been associated with the presence of SARS-CoV, MERS-CoV or SARS-CoV2 viraemia in affected patients. In vitro work has looked at the pattern of viral entry and release from polarised epithelial cells infected by coronaviruses. This work has demonstrated a correlation between the severity of a coronavirus infection and the ability of the virus to reach and infect the basal surface of host cells. It has been postulated that this ability helps the virus invade the bloodstream of the host, resulting in a systemic infection with multiple organ involvement. Here we propose that basal surface release and entry of COVID-19 into and out of cells at epithelial-endothelial interface plays a key pathogenic role in severe COVID-19 disease.
Fri, 29 May 2020
BRIEF REPORT | doi:10.20944/preprints202005.0466.v1
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; variant; low pathogenicity; Singapore
Online: 29 May 2020 (12:47:07 CEST)
Number of confirmed cases of COVID-19 caused by SARS-CoV-2 exceeded 5 million as of May 21, 2020. Global average of the case fatality rate of COVID-19 is about 7% so far. There exist variations in case fatality rates among countries. Particularly, Singapore and Qatar have exceptionally low case fatality rates with 0.1% while France’s rate is almost 20%. Since no magic bullet treatment for COVID-19 exists, we investigated SARS-CoV-2 strains specific to Singapore in this study to identify a clade with low pathogenicity. Variant analysis revealed that a clade with variants ORF1ab L3606F, A4489V, S2015R, T2016K, and N P13L is common in Singapore. Based on our analysis of variants and historical case statistics, the clade is dominant in a recent surge. Therefore, we suggest that low case fatality rate of Singapore possibly is attributed to the clade. Although contribution of each variant to the low pathogenicity is not clear, L3606F alone does not accomplish such low pathogenicity from the comparison with case fatality data from Japan, where L3606F is dominant. Further investigation is necessary to conclude to validate this finding.
Wed, 27 May 2020
REVIEW | doi:10.20944/preprints202005.0448.v1
Subject: Life Sciences, Virology Keywords: betacoronaviruses; genomics; SARS-CoV; MERS-CoV; SARS-CoV-2; COVID-19
Online: 27 May 2020 (08:50:46 CEST)
In the 21st century, three highly pathogenic betacoronaviruses have emerged, with an alarming rate of human morbidity and case fatality. Genomic information has been widely used to understand the pathogenesis, animal origin and mode of transmission of betacoronaviruses in the aftermath of the 2002-03 severe acute respiratory syndrome (SARS) and 2012 Middle East respiratory syndrome (MERS) outbreaks. Furthermore, genome sequencing and bioinformatic analysis have had an unprecedented relevance in the battle against the 2019-20 coronavirus disease 2019 (COVID-19) pandemic, the newest and most devastating outbreak caused by a coronavirus in the history of mankind, allowing the follow up of disease spread and transmission dynamics in near real time. Here, we review how genomic information has been used to tackle outbreaks caused by emerging, highly pathogenic, betacoronavirus strains, emphasizing on SARS-CoV, MERS-CoV and SARS-CoV-2.
Mon, 25 May 2020
Subject: Life Sciences, Virology Keywords: human coronavirus; SARS-CoV; MERS-CoV; SARS-CoV-2; envelope protein; immunopathology
Online: 25 May 2020 (17:54:57 CEST)
Since the severe acute respiratory syndrome (SARS) outbreak in 2003, human coronaviruses (hCoVs) have been identified as causative agents of severe acute respiratory tract infections. Two more hCoV outbreaks have since occurred, the most recent being SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19). The clinical presentation of SARS and MERS is remarkably similar to COVID-19, with hyperinflammation causing a severe form of the disease in some patients. Previous studies show that the expression of the SARS-CoV E protein is associated with the hyperinflammatory response that could culminate in acute respiratory distress syndrome (ARDS), a potentially fatal complication. This immune-mediated damage is largely caused by a cytokine storm, which is induced by significantly elevated levels of inflammatory cytokines interleukin (IL)-1beta and IL-6, which are partly mediated by the expression of the SARS-CoV E protein. The interaction between the SARS-CoV E protein and the host protein, syntenin, as well as the viroporin function of SARS-CoV E, are linked to this cytokine dysregulation. This review aims to compare the clinical presentation of virulent hCoVs with a specific focus on the cause of the immunopathology. The review also proposes that inhibition of IL-1beta and IL-6 in severe cases can improve patient outcome.
ARTICLE | doi:10.20944/preprints202005.0413.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; nucleocapsid (N); genomics; coronavirus; Wuhan; Pandemic
Online: 25 May 2020 (17:45:40 CEST)
Severe acute respiratory syndrome novel coronavirus 2 (SARS-CoV-2) has caused the global pandemic as COVID-19, which is the most notorious global public health crisis in the last 100 years. SARS-CoV-2 is composed of four structural proteins and several non-structured proteins. The multi-facet nucleocapsid (N) protein is the major component of structural proteins of CoVs, However, there are no dedicated genomic, sequences and structural analyses focusing on potential roles of N protein. Hence, there is an urgent requirement of a detailed study on N protein of SARS-CoV-2. Herein, we are presenting a comprehensive study on N protein from SARS-CoV-2. We have identified seven motifs conserved in the three major domains namely N-terminal domain, linker regions and the C-terminal domains. Out of seven motifs, six motifs are conserved across different members of coronaviridae, while motif4 is specific for SARS CoVs with potential amyloidogenic properties. Additionally, we report this protein has large patches of disordered regions flanking with these seven motifs. These motifs are hubs of epitopes with 67 experimentally verified epitopes from related viruses. We report the presence of three nuclear localization signals (NLS1-NLS3 mapped to 36-41, 256-26, and 363-389 residues, respectively) and two nuclear export signals (NES1-NLS2 from 151-161 and 217-230 residues, respectively) in the N protein of SARS-CoV-2. These deciphered two Q-patches as Q-patch1 and Q-patch2, mapped in the regions of 266-306, and 361-418 residues, which potentially help in the aggregation of the viral proteins along with 219LALLLLDR226 patch. Additionally, we have identified 14 antiviral drugs potentially binding to seven motifs of N-proteins using docking-based drug discovery methods.
Sun, 24 May 2020
ARTICLE | doi:10.20944/preprints202005.0407.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; spike protein; D614G mutation; genotype distribution; furin cleavage site; secondary structure; sequence analysis; homology modeling
Online: 24 May 2020 (20:31:16 CEST)
We analyzed the SARS-CoV-2 spike (S) protein amino acid sequence extracted from 11,542 viral genomic sequences submitted to the Global Initiative on Sharing All Influenza Data (GISAID) database through April 27, 2020. Consistent with prior reports, we found a major S protein mutation, D614 to G614, that was represented in 56% of all the analyzed sequences. All other mutations combined were less than 10%. After parsing the data geographically, we found most of the Chinese patient samples showed D614 (97%). By contrast, most patient samples in many European countries showed G614 (51 to 88%). In the United States, the genotypic distribution in California and Washington was similar to Asian countries, while the distribution in other US states was comparable to Europe. We observed a dramatic increase in the frequency of G614 over time in multiple regions, surpassing D614 when both were present, suggesting G614 S protein virus outcompetes D614 S protein virus. To gain insight into the consequences of the D614G mutation, homology modeling using a multi-template threading mechanism with ab initio structural refinement was performed for a region of the S protein (S591 to N710) spanning the D614G mutation and the S1 furin cleavage site. Molecular models of this region containing D614 or G614 revealed a major difference in secondary structure at the furin domain (RRARS, R682 to S686). The D614 model predicted a random coil structure in the furin domain whereas the G614 model predicted an alpha helix. Critical residues in the cleavage domain of G614 model were found to better align with the PDB structure of a furin inhibitor. Thus, homology modeling studies suggest a potential mechanism whereby the D614G mutation may confer a competitive advantage at the furin binding domain that may contribute to the rise of the D614G SARS-CoV-2 mutant.
ARTICLE | doi:10.20944/preprints202005.0396.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; coronavirus; variant analysis; phylogenetic analysis; viral evolution
Online: 24 May 2020 (18:25:47 CEST)
The severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) viral genome is an RNA virus consisting of approximately 30,000 bases. As part of testing efforts, whole genome sequencing of human isolates has resulted in over 1,600 complete genomes publicly available from GenBank. We have performed a comparative phylogenetic analysis of the sequences, in order to detect common mutations within the population. Analysis of variants occurring within the assembled genomes yields 417 variants occurring in at least 1% of the completed genomes, including 229 within the 5’ untranslated region (UTR), 152 within the 3’UTR, 2 within intergenic regions and 34 within coding sequences.
ARTICLE | doi:10.20944/preprints202005.0390.v1
Subject: Life Sciences, Virology Keywords: Zika; Yellow fever; cross reactive; flavivirus; congenital infection; enhancement
Online: 24 May 2020 (17:12:58 CEST)
Zika virus (ZIKV) is a flavivirus that originated in Africa but emerged in Latin America in 2015. In this region, other flaviviruses such as Dengue (DENV), West Nile, and Yellow Fever Virus (YFV) also circulate, allowing for possible antigenic cross-reactivity to impact viral infections and immune responses. Studies have found antibody mediated enhancement between DENV and ZIKV, but the impact of YFV antibodies on ZIKV infection has not been fully explored. ZIKV infections cause congenital syndromes, such as microcephaly, necessitating further research into ZIKV vertical transmission through the placental barrier. Recent advancements in biomedical engineering have generated co-culture methods that allow for in vitro recapitulation of the maternal: fetal interface. This study utilized a transwell assay, which is a co-culture model utilizing human placental syncytiotrophoblasts, fetal umbilical cells, and a differentiating embryoid body to replicate the maternal: fetal axis. To determine if cross reactive YFV vaccine antibodies impact the pathogenesis of ZIKV across the maternal fetal axis, maternal syncytiotrophoblasts were inoculated with ZIKV or ZIKV incubated with YFV vaccine anti-sera, and viral load was measured 72 hours post inoculation. The data show that the impact of YFV on ZIKV replication is cell line dependent. In differentiating embryoids, the presence of YFV antibodies enhanced ZIKV infection. Since viral pathogenesis, and the impact of antigenic cross-reactive antibodies, is cell line specific at the maternal-fetal axis, this suggests there may be discreet mechanisms that impact congenital ZIKV infections.
ARTICLE | doi:10.20944/preprints202005.0389.v1
Subject: Life Sciences, Virology Keywords: Asian citrus psyllid; citrus greening bacterium; huanglongbing; transcriptomics; virus-vector relationship; vitellogenin; cytoskeleton; endocytotic pathway
Online: 24 May 2020 (17:03:45 CEST)
Citrus greening disease or huanglongbing (HLB) caused by Candidatus Liberibacter asiaticus (CLas) limits the citrus production worldwide. CLas is transmitted by the Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Psyllidae) in a persistent-propagative manner. Application of insecticides to manage the psyllid vectors and disease is the most common practice. Understanding the molecular interaction between CLas and ACP and interrupting the interrelationship can provide an alternative to insecticides for managing citrus greening disease. Transcriptome analysis of ACP in response to CLas showed differential expression of 3911 genes (2196 up-regulated, and 1715 down-regulated) including the key genes of ACP involved in cytoskeleton synthesis and nutrition-related proteins. Majority of the differentially expressed genes were categorized under molecular function followed by cellular components and biological processes. KEGG pathway analysis showed differential regulation of carbohydrate, nucleotide and energy metabolic pathways, the endocytotic pathway and the defense-related pathways. Differential regulation of genes associated with the key pathways might favors CLas to become systemic and propagate in its insect vector. The study provides an understanding of genes involved in circulation of CLas in ACP. The candidate genes involved in key physiological processes and CLas transmission by ACP would be potential targets for sustainable management of ACP and CLas.
Sat, 23 May 2020
ARTICLE | doi:10.20944/preprints202005.0379.v1
Subject: Life Sciences, Virology Keywords: Coronaviruses; MERS-CoV; SARS-CoV-2; Serological assay; VSV pseudovirus
Online: 23 May 2020 (16:46:15 CEST)
Emerging highly pathogenic human coronaviruses (CoVs) represent a serious ongoing threat to the public health worldwide. The spike (S) proteins of CoVs are surface glycoproteins that facilitate viral entry into host cells via attachment to their respective cellular receptors. The S protein is believed to be a major immunogenic component of CoVs and a target for neutralizing antibodies (nAbs) and most candidate vaccines. Development of a safe and convenient assay is thus urgently needed to determine the prevalence of CoVs nAbs in the population, to study immune response in infected individuals, and to aid in vaccines and viral entry inhibitors evaluation. While live virus-based neutralization assays are used as gold standard serological methods to detect and measure nAbs, handling of highly pathogenic live CoVs requires strict bio-containment conditions in biosafety level-3 laboratories. On the other hand, use of replication-incompetent pseudoviruses bearing CoVs S proteins could represent a safe and useful method to detect nAbs in serum samples under biosafety level-2 conditions. Here, we describe a detailed protocol of a safe and convenient assay to generate vesicular stomatitis virus (VSV)-based pseudoviruses to evaluate and measure nAbs against highly pathogenic CoVs. The protocol covers methods to produce VSV pseudovirus bearing the S protein of the Middle East respiratory syndrome-CoV (MERS-CoV) and the severe acute respiratory syndrome-CoV-2 (SARS-CoV-2), pseudovirus titration, and pseudovirus neutralizing assay. Such assay could be adapted by different laboratories and researchers working on highly pathogenic CoVs without the need to handle live viruses in biosafety level-3 environment.
REVIEW | doi:10.20944/preprints202005.0376.v1
Subject: Life Sciences, Virology Keywords: virus bioinformatics; SARS-CoV-2; sequencing; epidemiology; drug design; tools
Online: 23 May 2020 (11:01:11 CEST)
SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a novel virus of the family Coronaviridae. The virus causes the infectious disease COVID-19. The biology of coronaviruses has been studied for many years. However, bioinformatics tools designed explicitly for SARS-CoV-2 have only recently been developed as a rapid reaction to the need for fast detection, understanding, and treatment of COVID-19. To control the ongoing COVID-19 pandemic, it is of utmost importance to get insight into the evolution and pathogenesis of the virus. In this review, we cover bioinformatics workflows and tools for the routine detection of SARS-CoV-2 infection, the reliable analysis of sequencing data, the tracking of the COVID-19 pandemic and evaluation of containment measures, the study of coronavirus evolution, the discovery of potential drug targets and development of therapeutic strategies. For each tool, we briefly describe its use case and how it advances research specifically for SARS-CoV-2. All tools are freely available online, either through web applications or public code repositories.
Subject: Life Sciences, Virology Keywords: anti-viral; COVID-19; SARS-CoV-2; autophagy; chloroquine; hydroxychloroquine; immunology; infection; inflammation; lysophagy; microbiology; Plaquenil; SARS; virophagy
Online: 23 May 2020 (10:45:40 CEST)
At a time when the world faces an emotional breakdown, crushing our dreams if not taking our lives, we realize that together we must fight the war against the COVID-19 outbreak even if almost the majority of the scientific community finds itself confined to home. Every day, like everyone else, we, scientists, listen to the latest news with its promises and announcements. Across the world, a surge of clinical trials trying to cure or slow down the coronavirus pandemic has been launched to bring hope instead of fear and despair. One first proposed clinical trial has drawn worldwide hype to the benefit of chloroquine (CQ), a well-known and broadly used anti-malarial drug, in the treatment of patients infected by the recently emerged deadly coronavirus (SARS-CoV-2). We should consider this information in the light of the long-standing anti-inflammatory and anti-viral properties of CQ-related drugs. Yet, none of the articles promoting the use of CQ in the current pandemic evoked a possible molecular or cellular mechanism of action that could account for any efficacy. Here, given the interaction of viruses with macroautophagy (hereafter referred to as autophagy), a CQ-sensitive anti-viral safeguard pathway, we would like to discuss the pros, but also the cons concerning the current therapeutic options targeting this process.
HYPOTHESIS | doi:10.20944/preprints202005.0359.v1
Online: 23 May 2020 (05:26:13 CEST)
Severe Covid-19 disease is associated with endothelial infection, viraemia, and multi-organ dysfunction. The process through which SARS-CoV2 causes severe disease is yet to be determined. Here, we propose that in severe Covid-19 infection, SARS-CoV2 reaches the host bloodstream by infecting endothelial cells through their basal surface. This occurs, independently of ACE2, through CD147, a putative SARS-CoV2 receptor. The pathway proposed here encourages research on the mechanisms mediating endothelial cell infection in Covid-19.
Thu, 21 May 2020
ARTICLE | doi:10.20944/preprints202004.0239.v5
Subject: Life Sciences, Virology Keywords: epidemic; caseload management; partial unlock; social distancing; overshoot; COVID-19; coronavirus; eco-nomic impact; ventilator utilization; SARS-CoV-2
Online: 21 May 2020 (04:13:13 CEST)
Objectives: We study partial unlock or reopening interaction with seasonal effects in a managed epidemic to quantify overshoot effects on small and large unlock steps and discover robust strategies for reducing overshoot. Methods: We simulate partial unlock of social distancing for epidemics over a range of replication factor, immunity duration and seasonality factor for strategies targeting immunity thresholds using overshoot optimization. Results: Seasonality change must be taken into account as one of the steps in an easing sequence, and a two step unlock, including seasonal effects, minimizes overshoot and deaths. It may cause undershoot, which causes rebounds and assists survival of the pathogen. Conclusions: Partial easing levels, even low levels for economic relief while waiting on a vaccine, have population immunity thresholds based on the reduced replication rates and may experience overshoot as well. We further find a two step strategy remains highly sensitive to variations in case ratio, replication factor, seasonality and timing. We demonstrate a three or more step strategy is more robust, and conclude that the best possible approach minimizes deaths under a range of likely actual conditions which include public response.
Wed, 20 May 2020
REVIEW | doi:10.20944/preprints202005.0316.v1
Subject: Life Sciences, Virology Keywords: RT-PCR; seroconversion; serum biomarkers; SARS-CoV2; neutralizing antibodies
Online: 20 May 2020 (04:10:24 CEST)
The progression of the recent COVID-19 pandemic surprised political authorities as well as scientists. The possibility to design powerful strategies for health care and preserving economic and social activities strongly relies on the capacity to monitor correctly the virus spreading and the immune response in the symptomatic and asymptomatic population. The available data relative to the first pandemic months indicate that the test reliability was progressively improved but also that the extremely variable methodologies used in the diagnostic studies generated data that are often not comparable. This condition prevents a simple metadata analysis for the identification of reliable diagnostics guidelines. Nevertheless, there are converging evidences that combinations of complementary approaches may enable more precise identification of virus infection. Furthermore, it appears that the similarities between SARS-CoV2 and the related types SARS-CoV1 and MERS that caused outbreaks in the last 20 years can be exploited to infer some information for which no direct evidence is still available
Sun, 17 May 2020
Subject: Life Sciences, Virology Keywords: ACE2; Spike protein; SARS-CoV2; death rate; polymorphism; isoform variant; CD157, sankramikogenomics
Online: 17 May 2020 (14:51:39 CEST)
The 2019-Novel Coronavirus has currently gripped the world in terror, affecting 210 countries and territories. Originating from Wuhan, Hubei province, China, the virus has spread so rapidly throughout the world and has already claimed 308,927 lives and is currently afflicting 4.6 million people. The US has over 1.48 million confirmed cases of COVID-19, followed by Spain, Italy, France, UK, Germany, Turkey, Russia, Iran, and China. On careful inspection of the COVID-19 statistics, a peculiar unsettling trend becomes apparent. Western European countries and the US appear to have difficulties in overcoming the catastrophe. In contrast, countries in East Asia, Middle East and mid-Europe have sorted out the situation. Here, we will highlight this trend and propose the importance of infection-genomics (sankramikogenomics), in understanding the susceptibility to COVID-19 and the severity of disease progress. More detailed, systematic evaluation may also identify more susceptible populations. We will also highlight mere 12-fold lower affinity is insufficient to ignore CD147, as interactions occur between tens of spike proteins and equal number of cell surface ACE2 and/or CD147. Thus, both receptors are important to understand sankramikogenomics and severity of COVID-19. The observed ethnic differences in COVID severities may be due to variations in structure or tissue-specific expression (alternate splicing and accessibility) of both the target receptors. Research on both receptors may help in designing improved therapeutic strategies to fight COVID-19. Similar to pharmacogenomics to drug development and precision medicine, Sankramikogenomics will become an important field in other infectious diseases and pathogenicity.
Sat, 16 May 2020
ARTICLE | doi:10.20944/preprints202004.0171.v2
Subject: Life Sciences, Virology Keywords: protein functional domains; short linear motifs; coronaviruses; COVID-19; severe acute respiratory syndrome-related coronavirus; 2019-nCoV; virus outbreak
Online: 16 May 2020 (18:54:17 CEST)
Although phylogenetic analysis shows coronaviruses (CoV) share similar genome sequences, CoVs encode different number of proteins (5 to 14), which has implication on viral pathogenicity and infection. Here, we aimed to identify (in-silico) the similarities between different members of coronavirus family. The analysis included 50 coronavirus proteomes, including SARS-CoV-2 (COVID-19), to find the variation of the number of protein functional motifs and domain in each coronavirus. For this role, we used the experimentally validated domain (motif) that known to be crucial for viral infection. Although human CoVs are classified within one genus, we found variations among them. SARS-CoV-1, SARS-CoV-2 and MERS-CoV encode different type of domains, which has implications on the molecular interactions triggered by each virus within human cells. Secondly, we used functional motifs to reconstruct the potential molecular pathways or interactions triggered by SARS-CoV-2 proteins within human cell.
ARTICLE | doi:10.20944/preprints202005.0271.v1
Online: 16 May 2020 (17:07:43 CEST)
Currently, with a large number of fatality rates, coronavirus disease-2019 (COVID-19) has emerged as a potential threat to human health worldwide. It has been well-known that severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is responsible for COVID-19 and World Health Organization (WHO) proclaimed the contagious disease as a global pandemic. Researchers from different parts of the world amalgamate together inquest of remedies for this deadly virus. Recently, it has been demonstrated that the spike glycoprotein (SGP) of SARS-CoV-2 is the mediator behind the entrance into the host cells. Our group has comprehensibly analyzed the SGP of SARS-CoV-2 through multiple sequence analysis along with the phylogenetic analysis. Further, this research work predicted the most immunogenic epitopes for both B-cell and T-cell. Notably, we focused mainly on major histocompatibility complex (MHC) class I potential peptides and predicted two epitopes; WTAGAAAYY and GAAAYYVGY, that bind with the MHC class I alleles which are further validated by molecular docking analysis. Furthermore, this study also proposed that the selected epitopes were shown availability in a greater range of the population. Hence, our study comes up with a strong base for the implementation of designing novel vaccine candidates against SARS-CoV-2, however adequate laboratory works will need to be conducted for the appropriate application.
ARTICLE | doi:10.20944/preprints202004.0239.v4
Subject: Life Sciences, Virology Keywords: epidemic; caseload management; partial unlock; social distancing; overshoot; COVID-19; coronavirus; eco-nomic impact; ventilator utilization; SARS-CoV-2
Online: 16 May 2020 (16:13:16 CEST)
This paper accounts in lives-saved partial unlock strategies that may be used to facilitate reopening economies that have been shut down due to an epidemic or pandemic. For this purpose it introduces a new approach to simulation using an internal SIR engine with seasonality, and external behavior forcing calibrated with case data to account for initial human behavior under social distancing. The overall method relies on public goal setting and both professional and public feedback behavior. In this way it avoids much of the chaotic sensitivity to parameters and divergence of predictions and behavior which undermine the public image of epidemiology models and create rebounds. We study reducing the total cases by controlling threshold overshoot as economies reopen, controlling medical resource utilization, and reducing economic shutdown duration, all of these across significant scenario variation. We provide a quantitative analysis of overshoot and demonstrate a two-step manual method as well as the feedback method of avoiding it. We show goal-managed partial unlock to manage critical resources has the consequential effects of reducing economic downtime and bringing the cumulative cases down about 9%-27%, thereby saving lives with some degree of certainty. The optimization of overshoot does leave some risk of creating a residual small infection existing on birth rate and migration, and we provide some guidelines for minimizing the risk. Effectiveness is demonstrated using COVID-19 actual data and parameters for other diseases with replication factors up to 15.
ARTICLE | doi:10.20944/preprints202005.0264.v1
Subject: Life Sciences, Virology Keywords: plaque assay; neutralization; SARS; SARS-CoV-2; coronavirus; Avicel; methylcellulose; COVID
Online: 16 May 2020 (15:51:52 CEST)
When working with the novel coronavirus SARS-CoV-2 during a pandemic response, having a rapid, reproducible and reliable assay for infectious virus quantitation and utilization for evaluation of potential therapeutics is critical. Compared to traditional agarose overlay plaques visualized with neutral red, assays performed with Avicel R RC-591 semi-solid overlay provide a simplified format for rapid and easy detection and neutralization testing. The method is easily modified for higher throughput using dispensers or automated processing. Fixation using formalin provides flexibility when dealing with pathogenic agents such as SARS-CoV-2 where tissue culture plates might be removed from biocontainment for staining. Although plaque assays are considered straightforward in principle, having an easily reproducible, consistent plaque assay is an invaluable tool.
Mon, 11 May 2020
ARTICLE | doi:10.20944/preprints202005.0198.v1
Subject: Life Sciences, Virology Keywords: de-MARylation; interferon-stimulated gene; inflammation; PARP14; ACE2; coronavirus
Online: 11 May 2020 (13:11:43 CEST)
As more cases of COVID-19 are studied and treated world-wide, it had become apparent that lethal and most severe cases of pneumonia are due to an out-of-control inflammatory response to the SARS-CoV2 virus. I explored the putative causes of this specific feature through a detailed genomic comparison with the closest SARS-CoV-2 relatives isolated from bats, as well as previous coronavirus strains responsible for the previous epidemics (SARS-CoV, and MERS-CoV). The high variability region of the nsp3 protein was confirmed to exhibit the most variations between closest strains. It was then studied in the context of physiological and molecular data available in the literature. A number of convergent findings point out de-mono-ADP-ribosylation (de-MARylation) of STAT1 by the SARS-CoV-2 nsp3 as a likely cause of the cytokine storm observed in the most severe cases of COVID-19. This may suggest new therapeutic approaches and an assay to predict the virulence of naturally circulating SARS-like animal coronaviruses.
Sun, 10 May 2020
CONCEPT PAPER | doi:10.20944/preprints202005.0182.v1
Subject: Life Sciences, Virology Keywords: Coronavirus Nsp proteins; ribosomal proteins homology; inhibition of ribosome turn over; rRNA methyltransferase; protein synthesis inhibition; low ATP formation; blood clotting; low blood pressure and coma
Online: 10 May 2020 (18:14:55 CEST)
Multi-Alignment method coupled with phylogenetic analysis we disclosed the Nsp9 and Nsp10 non-structural proteins of Corona Virus as rRNA RlmH/K methyltransferases with similarities with bin recombinase and int-core integrase fold. Further, Nsp9 has similarities to S8 ribosomal protein and Nap10 has similarity to S10 ribosomal protein. Previously, we showed Nsp13, Nsp14, Nsp15 and Nsp16 are also different types of rRNA RlmE/N and Cfr-like methyltransferases-ribonuclease with RNA helicase domains. Two domains of Nsp13 astonishingly have similarities to ribosomal proteins L6 and L9. Taken together, Nsp9/10 and Nsp13-16 proteins could mimic host ribosome assembly and also could methylate rRNA of mitobibosome preventing mitochondrial protein synthesis and oxidative phosphorylation. Low ATP synthesis causes lowering blood pressure following coma but very ATP concentration (1-10nM) surely induces platelets aggregation through vWA, collagen and GpIIb/IIIa proteins followed by fibrin formation and blood clotting as recently have seen in the lung of many Corona virus infected patients. We have also postulated that two polyproteins itself resemble like 28S and 38S mitoribosome subunits and compete with rRNAs inhibiting the ribosome turnover and new protein synthesis due to their similarities with many ribosomal proteins. Such finding may be valuable in computer-based novel drug design against Corona virus.
Subject: Life Sciences, Virology Keywords: coronavirus; COVID-19; pandemic; model; partial unlock; social distancing; economic impact; ventilator utilization; SARS-CV-2; overshoot
Online: 10 May 2020 (15:14:11 CEST)
This paper analyzes the stability and usefulness of a caseload management method for COVID-19 or similar epidemics and pandemics. It reduces the total cases by controlling overshoot as groups cross the herd immunity threshold, balances medical resource utilization, and subject to those two constraints reduces economic shutdown duration across significant scenario variation. A quantitative analysis of overshoot is provided. An SIR-type model was used with clear parameters suitable for public information with tracking and predictive capabilities is used. It contains a simulation of a decision-maker for select-day partial unlock so that many scenarios can be quickly and impartially analyzed. Using certain days of the week, already practiced by some countries, is not a necessary part of the method, but was used in the simulation to give a highly quantified unlock scheme. While the model shows total cumulative cases, and therefore deaths, declining initially with flattening, when flattening begins to produce large rebounds the death rate goes back up. Partial unlock to manage critical resources had the consequential effects of reducing economic downtime and bringing the cumulative cases down about 8-12% between now and the second half of 2021, thereby saving lives with some degree of certainty. The optimization of overshoot does leave some risk of creating a residual small infection existing on birth rate and migration, and we provide some guidelines for minimizing the risk.
Fri, 8 May 2020
BRIEF REPORT | doi:10.20944/preprints202005.0143.v1
Subject: Life Sciences, Virology Keywords: Covid-19; Epidemiology; Chronic diseases; Serious or critical cases; Brazil; Coronavirus
Online: 8 May 2020 (12:33:24 CEST)
Chronic noncommunicable diseases (CNCDs) have been a major public health concern worldwide, especially diabetes, cardiovascular disease, chronic obstructive pulmonary disease, hypertension, in addition to obesity, which is even more worrying when the subject involves the covid-19 pandemic, because such incidences correlate with the need for intensive care units, including the possibility of death of the patient. Therefore, for countries with the highest numbers of critical cases, it is important to assess the incidence of these diseases to guide the public that most needs guidance on public policies for social isolation.
COMMUNICATION | doi:10.20944/preprints202005.0138.v1
Subject: Life Sciences, Virology Keywords: covid-19; epidemiology; epidemiological week; Brazil; coronavirus; viruses
Online: 8 May 2020 (08:08:40 CEST)
Amid the covid-19 pandemic, other diseases, including viruses, are still acting to the detriment of their seasonality and risk factors for contagion. For this reason, it is interesting to know the degree of impact of other viruses, mainly respiratory, in which they have similar symptoms, in diagnoses for contamination by the new coronavirus based on epidemiological surveys, via epidemiological weeks, in Brazil. To what extent there may be a hypothesis of confusion of contaminated data, harming the health system, with regard to the need for intensive care units and control of viruses, and negatively or positively implying in the control or uncontrolling of viruses in general.
ARTICLE | doi:10.20944/preprints202005.0136.v1
Subject: Life Sciences, Virology Keywords: deubiquitination; leukemia; ubiquitin-specific protease 2 (USP2); SARS-CoV-2 papain-like protease (PLpro); COVID-19
Online: 8 May 2020 (03:45:22 CEST)
The ubiquitin-specific protease 2 (USP) belongs to the family of deubiquitinases and plays a critical role in tumors cells’ survival and therefore signifies an important therapeutic target. Previous studies have indicated promising efficacies of potent human USP2 inhibitors including, thiopurine analogues against SARS-CoV papain-like proteases (PLpro). The PLpro have significant functional implications in the innate immune response during SARS-CoV-2 infection and considered an important antiviral target. Both proteases share strikingly similar USP fold with right-handed thumb–palm–fingers structural scaffold and conserved catalytic triad Cys-His-Asp/Asn. In this urgency situation of COVID-19 outbreak, there is a lack of in-vitro facilities readily available to test SARS-CoV-2 inhibitors in whole-cell assays. Therefore, we adopted an alternate route to identify potential USP2 inhibitor through integrated structure-based virtual screening efforts. After a subsequent virtual screening protocol, the best compounds were selected and tested. The compound Z93 showed significant IC50 value against Jurkat (9.67 µM) and MOTL-4 cells (11.8 µM). The binding mode of Z93 was extensively analyzed through molecular docking, followed by MD simulations, and molecular interactions were compared with SARS-CoV-2. The relative binding poses of Z93 fitted well in the binding site of both proteases and showed consensus π-π stacking and H-bond interactions with histidine and aspartate/asparagine residues of the catalytic triad. These results led us to speculate that compound Z93 might be the first potential chemical lead against SARS-CoV-2 PLpro, which warrants in-vitro evaluations.
Wed, 6 May 2020
CONCEPT PAPER | doi:10.20944/preprints202005.0097.v1
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2–human carbohydrate interaction; trans-species glycosylation; A-like/Tn formation; glycan trans-species bridge
Online: 6 May 2020 (14:41:35 CEST)
While the ACE2 protein is defined as the primary SARS-CoV-2 receptor, the viral serine molecule, mobilized by the host's TMPRSS2 enzyme from the viral (S) spike protein, hijacks the GalNAc metabolism of the host, and the resulting hybrid, serologically A-like/Tn structure acts as a host–pathogen functional molecular bridge. In humans, this intermediate structure will hypothetically be replaced by ABO(H) blood group-specific, mucin-type structures, in the case of infection hybrid epitopes, implicating the phenotypically glycosidic accommodation of plasma proteins. The virus may, by mimicking the synthetic pathways of the ABO(H) blood groups, bind to the cell surfaces of the blood group O(H) by formation of a hybrid H-type antigen as the potential precursor of hybrid non-O blood groups, which does not affect the highly anti-glycan aggressive anti-A and anti-B isoagglutinin activities, exerted by the germline-encoded nonimmune IgM. In the non-O blood groups, which have developed from the H-type antigen, these IgM activities are downregulated by phenotypic glycosylation, while adaptive immunoglobulins might arise in response to the hybrid A and B blood group structures, suggesting the exertion of autoreactivity. The non-O blood groups thus become a preferred target for the virus, whereas blood group O(H) individuals, lacking the A/B phenotype-determining enzymes and binding the virus alone by hybrid H-type antigen formation, have the least molecular contact with the virus and maintain the critical anti-A and anti-B isoagglutinin activities, exerted by the ancestral IgM, which is considered the humoral spearhead of innate immunity.
Tue, 5 May 2020
BRIEF REPORT | doi:10.20944/preprints202005.0084.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; Vitamin D; Ivermectin; RNA-dependent-RNA polymerase; Spike glycoprotein; Knowledge based docking
Online: 5 May 2020 (15:18:30 CEST)
COVID-19 has emerged as deadly pandemic worldwide with no vaccine or suitable antiviral drugs to prevent or cure the disease. Because of the time-consuming process to develop new vaccines or antiviral agents, there has been a growing interest in repurposing some existing drugs to combat SARS-CoV-2. Vitamin D is known to be protective against acute respiratory distress syndrome (ARDS), pneumonia and cytokine storm. Recently it has been used as a repurposed drug for the treatment of H5N1 virus-induced lung injury. Circumstantial evidences indicate that people with low level of vitamin D are more susceptible to SARS-CoV-2. Although, vitamin D was suggested to interfere with viral replication, its interaction with any SARS-CoV-2 protein is unexplored yet. Beside this, ivermectin, a well-known anti-parasitic agent, exhibits potent anti-viral activities in vitro against viruses such as HIV-1 and dengue. Very recently, ivermectin has been found to reduce viral load of SARS-CoV-2 in vitro. We have analyzed available structures of SARS-CoV-2 proteins to identify probable binding partner(s) of vitamin D and ivermectin through knowledge-based docking studies and figured out possible implication of their binding in SARS-CoV-2 infection. Our observations suggest that the non-structural protein nsp7 possesses a potential site to house 25-hydroxyvitamin D3 (VDY) or the active form of Vitamin D, calcitrol. Binding of vitamin D with nsp7 likely to hamper the formation of nsp7-nsp8 complex which is required to bind with RNA dependent RNA polymerase (RdRP), nsp12 for optimal function. On the other hand, potential binding site of ivermectin has been identified in the S2 subunit of trimeric spike(S) glycoprotein of SARS-CoV-2. We propose that deeply inserted mode of ivermectin binding at three inter-subunit junctions may restrict large scale conformational changes of S2 helices which is necessary for efficient fusion of viral and host membrane. Our study, therefore, opens up avenues for further investigations to consider vitamin D and ivermectin as potential drugs against SARS-CoV-2.
REVIEW | doi:10.20944/preprints202005.0070.v1
Subject: Life Sciences, Virology Keywords: Covid; covid-19; sars-cov-2; temperature; heat; body temperature; air temperature; viral decay; viral stability; transmission; severity
Online: 5 May 2020 (10:47:18 CEST)
Air temperature and body temperature may influence COVID-19 disease severity and transmission rates. In vitro data indicate that SARS-CoV-2 loses infectivity at normal core body temperature (37°C); however, small reductions in temperature proximate to 37°C may result in substantially increased viral stability. If these results are representative of viral decay rates in vivo, then cooler temperatures in the body may enable more rapid viral growth. Breathing cool air—even as warm as 25°C—cools upper respiratory tract (URT) surfaces to several degrees below body temperature, and these lower temperatures may make the URT exceptionally conducive to SARS-CoV-2 replication. Increased URT viral load may enable more effective transmission. Additionally, because SARS-CoV-2 infection may frequently begin in the URT before spreading through the body, an increased rate of viral replication in the URT early in the disease course may result in more rapid progression of disease, potentially causing more severe adverse outcomes. Core body temperature may also be a factor in disease severity, as lower core body temperatures may enable more rapid viral growth. The significance of air temperature and body temperature to disease severity and transmission rates may inform preventative measures and post-exposure prophylaxis treatments for COVID-19.
REVIEW | doi:10.20944/preprints202004.0040.v3
Subject: Life Sciences, Virology Keywords: Dengue; COVID-19; SARS-CoV-2; epidemiology; infection; mortality; cross-protection; Dengue vaccine; ELISA; Dengvaxia
Online: 5 May 2020 (03:00:34 CEST)
Global severity maps of ongoing dengue epidemic and COVID-19 pandemic do not overlap. Countries with high dengue endemicity (>1.5 million cases/year) are observably less hit by COVID-19 in terms of infection, transmission and mortality. Based on non-overlap of dengue and COVID-19 severity maps and evidence of SARS-CoV-2 serological cross-reactions with dengue, we wonder whether immediate immunization of susceptible populations in Europe, North America and Asia (China, Iran) with available live-attenuated dengue vaccines, will cue the anti-viral immune response to thwart COVID-19 (viral interference). Risk of developing post-vaccination “Antibody-dependent Enhancement” is low as dengue is not endemic in the aforesaid regions.
Mon, 4 May 2020
CONCEPT PAPER | doi:10.20944/preprints202004.0310.v2
Subject: Life Sciences, Virology Keywords: ACE2; Spike protein; SARS-CoV2; death rate; polymorphism; isoform variant; CD157, sankramikogenomics
Online: 4 May 2020 (19:12:33 CEST)
The 2019-Novel Coronavirus has currently gripped the world in terror, affecting 210 countries and territories as of April 29, 2020. Originating from Wuhan, Hubei province, China, the virus has spread so rapidly throughout the world and has already claimed 218,000 lives and is currently afflicting 3.14 million people. The US has over 1.03 million confirmed cases of COVID-19, followed by Spain, Italy, France, UK, Germany, Turkey, Russia, Iran, and China. On careful inspection of the COVID-19 statistics, a peculiar unsettling trend becomes apparent. Western European countries and the US appear to have difficulties in overcoming the catastrophe. In contrast, countries in East Asia, Middle East and mid-Europe have sorted out the situation. Here, we will highlight this trend and propose the importance of infection-genomics (sankramikogenomics), in understanding the susceptibility to COVID-19 and the severity of disease progress. More detailed evaluation may also identify more susceptible populations. Such differences are due to variations in structure or tissue-specific expression (alternate splicing and accessibility) of the target receptors. So, we will highlight mere 12-fold lower affinity is insufficient to ignore CD147, as interactions occur between tens of spike proteins and equal number of cell surface ACE2 and/or CD147. Similar to pharmacogenomics to drug development and precision medicine, Sankramikogenomics will become an important field in other infectious diseases and pathogenicity.
Sat, 2 May 2020
ARTICLE | doi:10.20944/preprints202005.0022.v1
Online: 2 May 2020 (16:29:38 CEST)
During December 2019, a novel coronavirus named SARS-CoV-2 has emerged in Wuhan, China. The human to human transmission of this virus has also been established. The virus has so far infected more than 2 million people and spread over 200 countries. The World Health Organization (WHO) has declared COVID-19 a global health emergency due to its spread well beyond China. It has been established that this virus originates from bats and uses an intermediate host for transfer to humans. The knowledge about the intermediate host is important to find the virus shuttle mechanism to stop future outbreaks. For this, the genetic and structural analysis of coronaviruses spike proteins was performed using a computer-assisted approach.To conduct the In silico analysis, 43 sequences of spike protein belong to different species were retrieved from the NCBI nucleotide database. Pairwise and multiple sequence alignments were performed to check the similarities and differences of the retrieved sequences. Moreover, to highlight relationships among different species, phylogenetics analysis was performed using the MEGA software tool. In the end, protein structure alignment (superimposition) was performed against the reference structure by UCSF Chimera software. The results highlighted that the maximum similarity of human protein was found against Bat and Pangolinsequences. Moreover, among Bat and Pangolin, the highest similarity was found against pangolin based on phylogenetics analysis. These results suggest that SARS-CoV-2 transfers from bats to humans through pangolins.
HYPOTHESIS | doi:10.20944/preprints202005.0005.v1
Subject: Life Sciences, Virology Keywords: social intervention; COVID-19; health policy; public health; age; gender
Online: 2 May 2020 (12:04:58 CEST)
Many governments particularly in Europe are designing social interventions for the first post COVID-19 emergency phase. Definition of a ‘best practice’ for restriction release is urgent. Although data uncertainty generate difficulties, we believe near term analysis must shift from attempting to understand the numerous ‘unknowns’ to the clarification and interpretation of the few ‘knowns’, to create stepping stones towards rapid evidence-based decision making.Here, open access data on COVID-19 severity in three European countries were analyzed. Spain’s data were more comprehensive than those from Italy and Germany. Overall, COVID-19 severity shows a remarkable nonlinear growth with age that is significantly higher in adult males. Hence, age-adaptive and gender-balanced social interventions might represent efficient repopulation options for public health policymakers. Furthermore, we urge wider governmental effort for open access to relevant data. Their analysis will allow consolidation of existing trends, validation of key observations and thus facilitation of timely decisions.
Thu, 30 April 2020
ARTICLE | doi:10.20944/preprints202004.0535.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2 RNA Secondary Structure; Spike Protein; Furin; TMPRSS2
Online: 30 April 2020 (14:13:36 CEST)
Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) has claimed nearly 180,000 lives and continues to spread. There are currently no approved medications or vaccines for this new coronavirus. Studies have shown that the positive RNA genome of SARS-CoV-2 contains unique features, including a 12-base sequence inserted between the two subunits of viral receptor protein Spike. This inserted sequence facilitates the cleavage of Spike by the cellular proteases Furin and TMPRSS2, leading to the fusion of virus and host cell membranes. Current studies are mostly focused on the SARS-CoV-2 Spike protein and its interacting cellular proteins ACE2, Furin, and TMPRSS2. RNA structural studies are limited and little is known about the potential impact of the 12-base sequence insert on the secondary structure of SARS-CoV-2 genomic RNA and/or its transcripts. Here, by using local and global RNA secondary structure predictions, we show that the novel 12-base insert of SARS-CoV-2 genome likely induces a major RNA secondary structure change.
ARTICLE | doi:10.20944/preprints202004.0529.v1
Online: 30 April 2020 (11:15:17 CEST)
The novel respiratory disease COVID-19 has reached the status of worldwide pandemic and large efforts are currently being undertaken in molecularly characterizing the virus causing it, SARS-CoV-2. The genomic variability of SARS-CoV-2 specimens scattered across the globe can underly geographically specific etiological effects. In the present study, we gather the 10,014 SARS-CoV-2 complete genomes currently available thanks to the collection endeavor of the GISAID consortium and thousands of contributing laboratories. We analyze and annotate all SARS-CoV-2 mutations compared with the reference Wuhan genome NC_045512.2. Our analysis shows the prevalence of single nucleotide transitions as the major mutational type across the world. There exist at least three clades characterized by geographic and genomic specificity. In particular, the clade G, prevalent in Europe, carries a D614G mutation in the Spike protein, which is responsible for the initial interaction of the virus with the host human cell. Our analysis may drive local modulation of antiviral strategies based on the molecular specificities of this novel virus.
REVIEW | doi:10.20944/preprints202004.0526.v1
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; origin; transmission; epidemiology; signs and symptoms; diagnosis; treatment and prevention.
Online: 30 April 2020 (10:47:14 CEST)
The emergence of novel SARS-CoV-2 virus in China in December 2019 has turned into a global pandemic through continued spread beyond borders. This review was aimed to extract up-to-date information on the evolution, transmission, clinical manifestations, diagnosis, treatment and prevention of COVID-19 to fight against this common enemy. PubMed, Scopus and Google Scholar were the sources of literature; whereas CDC, WHO and Worldometer provided updated information. Bats served as the reservoirs of this virus while pangolin is believed as an intermediate host to transmit the virus to humans. Direct human-to-human and indirect transmissions were involved. Major clinical manifestations included fever, cough, fatigue, sputum production and shortness of breath. Chest radiographs mostly showed bilateral ground-glass opacities. Aged patients and patients with comorbidities had higher case fatality ratios. Critical cases were vulnerable to develop pneumonia, multi-organ failure and deaths. Overall situation in China has improved substantially. The European region and region of the Americas were the worst hit out of six WHO global regions. PCR based methods are used for the diagnosis of COVID-19. Severe/critical cases essentially require supportive or intensive cares. Avoiding exposure to COVID-19 is the best way to prevent the disease. Thus, this review provides a snapshot on COVID-19.
REVIEW | doi:10.20944/preprints202004.0514.v1
Subject: Life Sciences, Virology Keywords: virus-host interaction; human immunodeficiency virus; protein-protein interactions; OMICs; transcriptomics; network analysis
Online: 30 April 2020 (03:07:05 CEST)
The interaction of human immunodeficiency virus with human cells is responsible for all stages of the viral life cycle, from the infection of CD4+ cells to reverse transcription, integration, and the assembly of new viral particles. To date, a large amount of OMICs data as well as information from functional genomics screenings regarding the HIV-1-host interaction has been accumulated in the literature and in public databases. We processed databases containing HIV-host interactions and found 2910 HIV-1-human protein-protein interactions, mostly related to viral group M subtype B, 137 interactions between human and HIV-1 coding and non-coding RNAs, essential for viral lifecycle and cell defense mechanisms, 232 transcriptomics, 27 proteomics, and 34 epigenomics HIV-related experiments. Numerous studies regarding network-based analysis of corresponding OMICs data have been published in recent years. We overview various types of molecular networks, which can be created using OMICs data, including HIV-human protein-protein interaction networks, co-expression networks, gene regulatory and signaling networks, and approaches for the analysis of their topology and dynamics. The network-based analysis can be used to determine the critical pathways and key proteins involved in the HIV life cycle, cellular and immune responses to infection, viral escape from host defense mechanisms, and mechanisms mediating different susceptibility of humans to infection. The proteins and pathways identified in these studies may represent a basis for developing new anti-HIV therapeutic strategies such as new small-molecule drugs preventing infection of CD4+ cells and viral replication, effective vaccines, "shock and kill" and "block and lock" approaches to cure latent infection.
Tue, 28 April 2020
Online: 28 April 2020 (07:50:12 CEST)
There were warnings before; nevertheless the current CoVID-19 pandemic took the world by surprise: within just four month, it conquered the globe and claimed over 200'000 lives. Unprecedented governmental actions put about half of the population under curfew or lock-down. The resulting economic meltdown is expected to eliminate globally 9’000’000’000’000 (9 trillion) USD in 2020 and 2021 alone, a value roughly the size of the yearly GDP of the world’s 150 smallest economies. The resulting crises might cause mass-unemployment and a hunger pandemic later this year. This Essay analyses current statistical data of the CoVID-19 pandemic to develop a guideline for a path through the crisis, minimizing both loss of lives and economic costs. Part 1 details the current situation; part 2 develops a small set of measures, allowing a near normal life until a future vaccination campaign has reached sufficient numbers of people; and part 3 provides some important lessons for the future beyond SARS-CoV-2. The Essay leads to the following key-messages: 1) The CoVID-19 pandemic will stay for at least two more years. This is the minimum time required for a vaccination campaign to reach sufficient numbers of people. 2) The crucial element to control the pandemic is keeping case numbers under the threshold required for a functional tracing, testing & isolation (TTI) strategy. That threshold differs from country to country and strongly depends on culture and the applied tracing technology as well as available testing capacities. 3) The economic burden of a TTI strategy is moderate while fatalities are also reduced. Hence, such an approach is strongly recommended. Its implementation requires a set of simple and cost-effective measures (see figure below), which in combination seem to be sufficient to keep CoVID-2’s reproductive rate at or below 1. 4) Implementing international coordination of actions will be necessary for effective infection-chain tracing5) If case numbers are above the TTI threshold, shutdown measures remain the only option until tracing of infection chains becomes feasible again.6) In the future, neglected pandemic-related research requires a funding boost. Just 1% of the bill of the current crisis could support the research of 45’000 scientist for 20 years.
Mon, 27 April 2020
Online: 27 April 2020 (09:55:03 CEST)
Severe acute respiratory syndrome coronavirus 2 (SARS coronavirus 2 or SARS-CoV-2) is the cause of the respiratory infection known as COVID-19. From an immunopathological standpoint, coronaviruses such as SARS-CoV-2 induce an increase in a variety of T-helper 1 (Th1) and inflammatory cytokines and chemokines including interleukins IL-1, IL-6, CCL2 protein and CXCL10 protein. In the absence of proven antiviral agents or an effective vaccine, substances with immunomodulatory activity may be able to inhibit inflammatory and Th1 cytokines and/or yield an anti-inflammatory and/or Th2 immune response to counteract COVID-19 symptoms and severity. This report briefly describes four unconventional but commercially accessible immunomodulatory agents that could be employed in clinical trials to evaluate their effectiveness at alleviating disease symptoms and severity: Low-dose oral interferon-alpha, microdose DNA, low-dose thimerosal and phytocannabinoids.
Sat, 25 April 2020
ARTICLE | doi:10.20944/preprints202004.0462.v1
Online: 25 April 2020 (11:18:57 CEST)
The induction of acoustic-mechanical oscillations to virus particles by illuminating them with microwave signals is analyzed theoretically. Assuming the virus particle being of spherical shape, its capsid consisting primarily of glycoproteins, a viscous fluid model is adopted while the outside medium of the sphere is taken to be ideal fluid. The electrical charge distribution of virus particle is assumed to be spherically symmetric with a variation along the radius. The generated acoustic-mechanical oscillations are computed by solving a boundary value problem analytically, making use of the Green’s function approach. Resonance conditions to achieve maximum energy transfer from microwave radiation to acoustic oscillation to the particle is investigated. Estimation of the feasibility of the technique to compete virus epidemics either for sterilization of spaces and/or use for future therapeutic applications is examined briefly.
Fri, 24 April 2020
ARTICLE | doi:10.20944/preprints202004.0450.v1
Online: 24 April 2020 (14:19:02 CEST)
Till date there are three full length COVID 19 virus genome sequences available from India. The earlier two were reported from Kerala, Southern India and the more recent one has been reported from Gujarat, western part of India. In this paper we report two novel mutations in the Spike protein sequence of Gujarat’s isolate. These mutations are based on comparison with the original Wuhan sequence. The two mutations have been found to be located just upstream and downstream of the receptor binding domain (RBD). Out of these two one has also been found to affect the secondary structure of the S1 domain. Since both of these mutations lie near the receptor binding domain, they might influence the spike receptor interactions by changing the conformation of the spike protein S1 domain. These mutations are uniquely placed and might be important in the context of vaccine engineering and therapeutic interventions.
Thu, 23 April 2020
COMMUNICATION | doi:10.20944/preprints202004.0414.v1
Subject: Life Sciences, Virology Keywords: COVID-19; infectious disease; transmission; response; Africa
Online: 23 April 2020 (11:41:54 CEST)
Coronavirus disease 2019 (COVID-19) since its declaration as a pandemic by world health organization (WHO) has spread across the various continent with little known about the most effective public health response for containing and mitigating the transmission of the epidemic. It is important to state that some authors have published on the lessons learned from transmission and management of COVID-19 infection but only a few considered it from the Africa perspective. Despite the late arrival of the pandemic in Africa and the notion that the virus may not thrive because of the high temperature in the continent; today the narrative has changed with the number of infected patients increasing daily. Herein, the authors have shared their perspectives and opinions on the dynamics and response to COVID-19 from Africa context to create more awareness and approach in mitigating the spread of the virus should the continent becomes the epicenter of COVID-19.
Wed, 22 April 2020
HYPOTHESIS | doi:10.20944/preprints202004.0151.v2
Online: 22 April 2020 (09:46:54 CEST)
Human respiratory beta coronavirus are emerging causes for Public Health Emergencies of International Concern (PHEIC). SARS-CoV2 is circulating worldwide since November 2019. We review here the cardiovascular morbidity and mortality in COVID-19, and data supporting the role for dysregulation of the RAS counterregulatory axis due to binding of SARS-CoV2 S protein to ACE2 receptor. Since this counterregulatory axis provides benefits not only on the cardiovascular front but also in acute lung injury, we speculate on potential use of ACE inhibitors and AT1R blockers in critically ill COVID-19 patients, and report current evidences.
ARTICLE | doi:10.20944/preprints202004.0390.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; SARS-CoV; ACE2; spike protein; phosphorylation; O-β-GlcNAcylation; molecular docking; chloroquine; 2-hydroxybenzohydrazine
Online: 22 April 2020 (06:01:00 CEST)
The novel coronavirus COVID- 19 disease is extremely contagious and has been spread worldwide. First COVID-19 case was identified in December, 2019 and within three months, more than one million affected cases and over 65,000 deaths have been reported. SARS-coronavirus 2 (SARS-CoV-2) also known as 2019-nCoV is a causative agent of COVID-19 disease and belongs to the SARS CoV (Severe Acute Respiratory Syndrome corona virus) family. The SARS-CoV-2 enters the human body by binding its viral surface spike protein with the host angiotensin-converting enzyme 2 (ACE2) receptors and cause infection. To prevent the virus entry and its transmission in the human body, we focused on the two domains of ACE2: i) the N-terminal extracellular binding domain (18-740 residues) reported for coronavirus spike interaction, and ii) the C-terminal cytoplasmic region (762-805 residues) to prevent the virus transmission. Therefore, we proposed: i) inhibition of receptor binding domain (RBD) of SARS-CoV-2 and human ACE2 protein may prevent the virus entry to the host and ii) inhibition of phosphorylation at Ser-787 of ACE2 protein may prevent the transmission of the virus in the COVID-19 patients. In the past, the critical role of Ser 787 in human ACE2 protein has been experimentally verified in SARS-CoV transmission, that upon binding to the receptor, SARS- CoV induces CKII- mediated phosphorylation of ACE2 at Ser-787 that in-turn facilitate virus entry to host cells, followed by replication and activation of ACE2, initiates downstream signaling leading to lung fibrosis. Therefore, in this study, we have suggested post-translational modification (PTM) O-β-GlcNAcylation, and two compounds Chloroquine and 2-hydroxybenzohydrazine might share the common pathways to prevent the COVID-19 infection in human. The addition of O-β-GlcNAcylation at same or neighboring Ser/ Thr residues results in phosphorylation inhibition and a change in protein structural and functional confirmations. Thereby, using neural networking methods, we have identified Ser/ Thr residues in ACE2 that are potential sites for phosphorylation and / or O-β-GlcNAcylation. Molecular docking showed that UDP-GlcNAc has more binding affinity with Ser-787 than the phosphoryl group. Moreover, chloroquine and 2-hydroxybenzohydrazine also showed great potential to bind at Ser-787 that may result in inhibition of Ser-787 phosphorylation and downstream signaling. Furthermore, O-β-GlcNAcylation, chloroquine and 2-hydroxybenzohydrazine showed their high affinity at ACE2-SARS-CoV-2receptor binding domain that may prevent the entry of SARS-CoV-2 into human body. In conclusion, inhibition of human ACE2 phosphorylation at Ser-787 and ACE2-SARS-CoV-2 binding domain could be promising targets against SARS-CoV-2 infection.
Tue, 21 April 2020
Subject: Life Sciences, Virology Keywords: Ebola virus; filovirus; inclusion bodies; CAD; pyrimidine synthesis
Online: 21 April 2020 (09:48:15 CEST)
Ebola virus (EBOV) is a zoonotic pathogen causing severe hemorrhagic fevers in humans and non-human primates with high case fatality rates. In recent years, the number and extent of outbreaks has increased, highlighting the importance of better understanding the molecular aspects of EBOV infection and host cell interactions to control this virus more efficiently. Many viruses, including EBOV, have been shown to recruit host proteins for different viral processes. Based on a genome-wide siRNA screen, we recently identified the cellular host factor carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) to be involved in EBOV RNA synthesis. However, mechanistic details of how this host factor plays a role in the EBOV life cycle remain elusive. In this study, we analyzed the functional and molecular interactions between EBOV and CAD. To this end, we used siRNA knockdowns in combination with various reverse-genetics based lifecycle-modelling systems and additionally performed co-immunoprecipitation and co immunofluorescence assays to investigate the influence of CAD on individual aspects of the EBOV life cycle and to characterize the interactions of CAD with viral proteins. Following this approach, we could demonstrate that CAD directly interacts with the EBOV nucleoprotein NP, and that NP is sufficient to recruit CAD into inclusion bodies dependent on the GLN-domain of CAD. Further, siRNA knockdown experiments indicated that CAD is important for both viral genome replication and transcription, while substrate rescue experiments showed that the function of CAD in pyrimidine synthesis is indeed required for those processes. Together this suggests that NP recruits CAD into inclusion bodies via its GLN domain in order to provide pyrimidines for EBOV genome replication and transcription. These results define a novel mechanism by which EBOV hijacks host cell pathways in order to facilitate genome replication and transcription, and provide further basis for the development of host directed broad spectrum antivirals.
CONCEPT PAPER | doi:10.20944/preprints202004.0381.v1
Subject: Life Sciences, Virology Keywords: hydroxychloroquine; COVID-19; immunomodulator; cytokine storm; flow chemistry
Online: 21 April 2020 (08:26:31 CEST)
Hydroxychloroquine, a known antiviral metabolite of chloroquine, is increasingly used along with antibiotic azithromycin for the treatment of COVID-19 infection. In about one month India, the world’s largest manufacturer, delivered hydroxychloroquine for treating COVID-19 to over 50 countries. The therapy is being used across the world both for patients staying at home at the early phase of symptoms, as well as for patients hospitalized. We summarize achievements as of late April 2020, review possible modes of action and suggest avenues for the quick scale-up of production of hydroxychloroquine.
REVIEW | doi:10.20944/preprints202004.0377.v1
Online: 21 April 2020 (06:56:12 CEST)
SARS-CoV-2 is a novel coronavirus that is the causative agent of Coronavirus infectious disease 2019 (COVD-19). As of the 17th April 2020, it has infected 2 114 269 people resulting in 145 144 deaths. The timing, magnitude and longevity of humoral immunity is not yet understood for SARS-CoV-2. Nevertheless, understanding this is urgently required to inform the likely future dynamics of the pandemic, to guide strategies to allow relaxation of social distancing measures and to understand how to deploy limiting vaccine doses when they become available to achieve maximum impact. SARS-CoV-2 is the seventh human coronavirus to be described. Four human coronaviruses circulate seasonally and cause common colds. Two other coronaviruses, SARS and MERS, have crossed from animal sources into humans but have not become endemic. Here we review what is known about the human humoral immune response to epidemic SARS CoV and MERS CoV and to the seasonal, endemic coronaviruses. Then we summarize recent, mostly non-peer reviewed studies into SARS-CoV-2 serology and reinfection in humans and non-human primates and summarize current pressing research needs.
REVIEW | doi:10.20944/preprints202004.0372.v1
Online: 21 April 2020 (04:44:40 CEST)
The recent pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread so rapidly and severely affected the people of almost every country in the world. The highly contagious nature of this virus makes it difficult to take control of the present pandemic situation. With no specific treatment available, the coronavirus disease 2019 (COVID-19) presents a threat to people of all ages including the elderly people and people with other medical complications as a vulnerable group to this disease. Better understanding of viral pathogenesis, appropriate preventive measures, early diagnosis and supportive treatments of the infected patients are now the general solutions to fight against this viral transmission. But, as an emerging disease, most about it remains still poorly understood. This article holds an overview on the origin and structure, pathogenesis, diagnosis and possible therapeutic options for the causative agent, SARS-CoV-2 and disease, COVID-19. However, few therapeutic options, laboratory experiments and other strategies proposed here need to be further clinically tested.
Mon, 20 April 2020
ARTICLE | doi:10.20944/preprints202004.0369.v1
Online: 20 April 2020 (16:01:29 CEST)
Background: Respiratory transmission is the primary route of SARS-CoV-2 infection. Angiotensin I converting enzyme 2 (ACE2) is the known receptor of SARS-CoV-2 spike glycoprotein for entry into human cells. A recent study reported absent to low ACE2 promoter activity in a variety of human lung epithelial cell samples. Three bioprojects (PRJEB4337, PRJNA270632 and PRJNA280600) invariably found abundant expression of ACE in human lungs compared to very low expression of ACE2. Methods: In silico tools were applied to assess potential interaction of SARS-CoV-2 surface spike protein with human ACE as well as predict the drugs that may block SARS-CoV-2 interaction with host receptor. Results: Although it is not obvious from the primary sequence alignment of ACE2 and its homolog ACE (also known as ACE1), comparison of X-ray crystallographic structures show striking similarity in the regions of these proteins which is known (for ACE2) to interact with the receptor binding domain (RBD) of SARS-CoV-2 spike protein. Critical amino acids that mediate interaction with the viral spike protein in ACE2 are organized in the same order in ACE. In silico analyses predicts comparable interaction of SARS-CoV-2 spike protein with ACE2 and ACE. In addition, this study predicts and selects already approved drugs from a list of 1263, which may interfere with the binding of SARS-CoV-2 spike glycoprotein to ACE2 and/or ACE.
Sun, 19 April 2020
ARTICLE | doi:10.20944/preprints202004.0347.v1
Subject: Life Sciences, Virology Keywords: antiviral peptides; COVID-19; SARS-CoV-2; nCoV-19; peptide design; ACE2; Spike protein
Online: 19 April 2020 (13:21:44 CEST)
Background: There are no known medicines or vaccines to control the COVID-19 pandemic caused by SARS-CoV-2 (nCoV). Antiviral peptides are superior to conventional drugs and may also be effective against COVID-19. Hence, we investigated the SARS-CoV-2 Spike RBD (nCoV-RBD) that interacts with hACE2 for viral attachment and entry. Methods: Three strategies and bioinformatics approaches were employed to design potential nCoV-RBD - hACE2 interaction-blocking peptides that may restrict viral attachment and entry. Firstly, the key residues interacting with nCoV-RBD - hACE2 are identified and hACE2 sequence based peptides are designed. Second, peptides from five antibacterial peptide databases that block nCoV-RBD are identified; finally, a chimeric peptide design approach is used to design peptides that can bind to key nCoV-RBD residues. The final peptides are selected based on their physiochemical properties, numbers and positions of key residues binding, binding energy, and antiviral properties. Results: We found (i) three amino acid stretches in hACE2 interact with nCoV-RBD; (ii) effective peptides must bind to three key positions of nCoV-RBD: Gly485/Phe486/Asn487, Gln493, and Gln498/Thr500/Asn501; (iii) Phe486, Gln493, and Asn501 are critical residues; (iv) AC20 and AC23 derived from hACE2 may block two key critical positions; (iv) DBP6 identified from databases can block the three sites of the nCoV-RBD interacting with one critical position Gln498; (v) seven chimeric peptides were considered promising among which cnCoVP-3, cnCoVP-4, and cnCoVP-7 are the top three; and (vi) cnCoVP-4 meets all the criteria and is the best peptide. Conclusion: All the ten peptides need experimental validation for their therapeutic efficacy.
REVIEW | doi:10.20944/preprints202004.0341.v1
Subject: Life Sciences, Virology Keywords: COVID-19; Outbreak; nCoV-19; Quinine; Chloroquine; Hydroxychloroquine
Online: 19 April 2020 (08:36:55 CEST)
Quinine and its less toxic derivatives have served humanity for decades as potent antimalarial drugs. Emergence of drug resistance has narrowed the usage of these drugs in malaria prevention and treatment. Fortunately, these drugs have roles in the treatment of other diseases as well including rheumatic disorders and viral infections. Quinine derivatives have proven antiviral effects, especially against human immunodeficiency virus (HIV), Zika virus (ZiKV), herpes simplex virus (HSV), Ebola virus and dengue virus (DENV). The prophylactic and therapeutic role of Chloroquine/hydroxychroquine has become a topic of interest after the recent outbreak of novel Corona virus-19 (nCoV-19). This virus is also named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and WHO has officially named this disease as Corona virus disease 2019 (COVID-19). This lethal virus has affected almost 186 countries of the world till to date just in a period of four months of its outbreak. No approved antiviral drug is existed for the treatment of COVID-19. Therefore, this review is focused on potential prophylactic and therapeutic role of chloroquine/hydroxychlroquine for COVID-19.
SHORT NOTE | doi:10.20944/preprints202003.0077.v4
The Ongoing COVID-19 Epidemic Curves Indicate Initial Point Spread in China With Log-Normal Distribution of New Cases per Day With a Predictable Last Date of the Outbreak Version 4: Predictions for Selected European Countries, USA and the World as a Whole and Try to Predict the End of the Outbreak Including a Discussion of a Possible “New Normal”
Online: 19 April 2020 (08:15:10 CEST)
During an epidemic outbreak it is useful for planners and responsible authorities to be able to plan ahead to estimate when an outbreak of an epidemic is likely to ease and when the last case can be predicted in their area of responsibility. Theoretically this could be done for a point source epidemic using epidemic curve forecasting. The extensive data now coming out of China makes it possible to test if this can be done using MS Excel a standard spreadsheet program available to most offices. The available data is divided up for whole China and the different provinces. This and the high number of cases makes the analysis possible. Data for new confirmed infections for Hubei, Hubei outside Wuhan, China excluding Hubei as well as Zhejiang and Fujian provinces all follow a log-normal distribution that can be used to make a rough estimate for the date of the last new confirmed cases in respective areas. In the version 2 continuation work, 9 additional days were added for the Chinese data to evaluate the previous predictions. The extra data then available from China follows the previous predicted trend supporting the usefulness of this simple technique. In the version 2 we also tested the feasibility for a non-specialist to make similar predictions using additional data from S Korea now available. In this third continuation the predictions for Version 2 are evaluated for S Korea and fits well the beginning of the decline but it seems to be difficult to bring down numbers of cases per day under about 100 new cases per day, potential reasons for this is discussed. To further evaluate when in a prediction becomes reliable the Chinese data was used to evaluate to make predictions for each day around the peak in number of cases and after2-3 consecutive days of decreasing new cases per day the prediction becomes reliable. In version 3 data for Italy just reaching this point was used to make further predictions for that country. A second new analysis was also added to use the fitted equation to detect when the acceleration of new cases per day stopped increasing exponentially. In the Chinese case this measured point coincides with the date of the complete Hubei lockdown and in the new Italian analysis it coincides with the mandatory Italian lockdown. Predicted dates for the end of the Italian outbreak is also added. In version 4 we expand the analysis to selected European countries, USA and the World as a whole and try to predict the end of the outbreak. We further discuss the apparent success of the used techniques that might work to introduce a “new normal” not very different to the previous to stop secondary outbreaks of COVID19 and future COVIDs that are sure to come.
REVIEW | doi:10.20944/preprints202004.0326.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; COVID-19; neutralizing antibodies; immunotherapy; vaccine
Online: 19 April 2020 (04:52:17 CEST)
We review aspects of the antibody response to SARS-CoV-2, the causative agent of the COVID- 19 pandemic. The topics we cover are relevant to immunotherapy with plasma from recovered patients and with monoclonal antibodies against the viral S-protein. The development of vaccines against SARS-CoV-2, an essential public health tool, will also be informed by an understanding of the antibody response in infected patients. Although virus-neutralizing antibodies are likely to protect, antibodies could potentially trigger immunopathogenic events in SARS-CoV-2-infected patients or enhance infection. An awareness of these possibilities may benefit clinicians and the developers of antibody-based therapies and vaccines.
CONCEPT PAPER | doi:10.20944/preprints202004.0310.v1
Subject: Life Sciences, Virology Keywords: ACE2; Spike protein; SARS-CoV2; death rate; polymorphism; isoform variant
Online: 19 April 2020 (01:35:58 CEST)
The 2019-Novel Coronavirus has currently gripped the world in terror, affecting 210 countries and territories as of April 17, 2020. Originating from Wuhan, Hubei province, China, the virus has spread so rapidly throughout the world and has already claimed 144,700 lives and is currently afflicting 2.17 million people. The US has over 677,000 confirmed cases of COVID-19, followed by Spain, Italy, France, Germany, UK and China. On careful inspection of the COVID-19 statistics, a peculiar unsettling trend becomes apparent. Here, I will highlight this trend and propose the importance of infection-genomics (sankramikogenomics), in understanding the susceptibility to COVID-19 and the severity of disease progress.
Fri, 17 April 2020
ARTICLE | doi:10.20944/preprints202004.0239.v2
Subject: Life Sciences, Virology Keywords: coronavirus; COVID-19; pandemic; model; partial unlock; social distancing; economic impact; ventilator utilization; SARS-CV-2; overshoot
Online: 17 April 2020 (08:48:55 CEST)
This paper analyzes the stability and usefulness of a caseload management method for COVID-19 or similar epidemics and pandemics. It reduces the total cases by controlling overshoot as groups cross the herd immunity threshold, balances medical resource utilization, and subject to those two constraints reduces economic shutdown duration across significant scenario variation. A quantitative analysis of overshoot is provided. An SIR-type model was used with clear parameters suitable for public information with tracking and predictive capabilities is used. It contains a simulation of a decision-maker for select-day partial unlock so that many scenarios can be quickly and impartially analyzed. Using certain days of the week, already practiced by some countries, is not a necessary part of the method, but was used in the simulation to give a highly quantified unlock scheme. While the model shows total cumulative cases, and therefore deaths, declining initially with flattening, when flattening begins to produce large rebounds the death rate goes back up. Partial unlock to manage critical resources had the consequential effects of reducing economic downtime and bringing the cumulative cases down about 8-12% between now and the second half of 2021, thereby saving lives with some degree of certainty. A gentle and decreasing slope of the increase in cases, which directly reduces total cases by avoiding overshoot, is difficult to accomplish by any other method.
Thu, 16 April 2020
ARTICLE | doi:10.20944/preprints202004.0287.v1
Online: 16 April 2020 (16:30:09 CEST)
COVID-19 virus has become a global threat to the human population and society. The virus which originated from China in December, 2019 has swept across continents in the world. Cameroon has been one of the countries with a high infectious rate in the recent period having a majority of the infectious cases in the Littoral region. Lack of awareness play a major role in the rise of COVID-19 cases. This paper examined the perceptions of the existence and spread of the COVID-19 virus in Wouri Division, Littoral Region of Cameroon. The study involved a qualitative survey designed by online questionnaires which were forwarded to the inhabitants of Wouri Division through e-mails and ‘WhatsApp’. The survey included the perception of the origin and existence of the COVID-19 virus, its mode of disease transmission, preventive and control measures. A total of 573 respondents were obtained (317 females and 256 males). From the results, although a greater proportion of the respondents showed knowledge towards the COVID- 19 virus existence, transmission and prevention that could lead to a reduction in the spread of the disease, our findings suggested that there’s more need for public sensitisation of the virus especially its method of transmission, control and prevention.
HYPOTHESIS | doi:10.20944/preprints202004.0286.v1
Subject: Life Sciences, Virology Keywords: SARS-CoV-2; domain-fold; evolutionary fingerprint; conserved domain; point mutation; recombination
Online: 16 April 2020 (16:13:13 CEST)
The high transmissibility and replication of SARS-CoV-2 have been attributed to enhanced protein functions which are dependent on protein folding. Our in silico study endeavored to scrutinize SARS-CoV-2 ORF1ab by analyzing the conserved folding patterns of its transcribed proteins. Accordingly, the findings indicated that SARS-CoV-2 ORF1ab shares domain-specific fold-fingerprints with a spectrum of unrelated organisms. Closer observation revealed slight changes in folding patterns engendered with small variation in the intrinsic amino acid sequence. By correlating with the evolvability-potential of RNA-viruses and COVID-19 pandemic, we hypothesize that SARS-CoV-2 could undergo fast recombination with the host, SARS-CoV-2 minor variants and other viral species resulting in a reservoir of SARS-CoV-2 quasispecies. It is highly possible that natural selection will cause a future emergence of evolved SARS-CoV-2-descendants. Nonetheless, we hope that this insightful study will assist in elucidating SARS-CoV-2 protein functionalities, development of vaccines, and the possibility and nature of future emergence.
CONCEPT PAPER | doi:10.20944/preprints202004.0282.v1
Online: 16 April 2020 (15:44:39 CEST)
Purpose: Pandemic Novel Coronavirus (SARS-CoV-2) has emerger centered from wuhan, China. Structurally homologous spike protein of SARS-CoV-2 receptor is taxonomically homologous with SARS-Cov and SARS associated bat coronavirus. Still now scientists are trying to find out proper vaccine and treatments for this disease. Methods: Systematically we modeled and compared the structure of SARS-CoV-2 spike protein along with Bat Cov, Bat SARS Cov and SARS Cov Urbani. S1 and S2 unit of the coronavirus (SARS-CoV-2) are attached with ACE2 and furin, here we docked 5 Ca+ chelating drugs with these two proteins. Results: Structural comparison with all these spike proteins revealed that less significant but not negligible difference exists among them. Inserted stable nucleotide sequences and corresponding surface exposed peptidal region may be considered as epitope. Docking result with Toxicokinetics and half life of Penicillamine can effectly inhibit the attachment site of spike protein of coronavirus (SARS-CoV-2). Conclusions: Docking summery and the pharmacokinetics with toxicokinetics index recommend that Penicillamine can able to inhibit the infection of SARS-CoV-2.
Wed, 15 April 2020
ARTICLE | doi:10.20944/preprints202004.0239.v1
Subject: Life Sciences, Virology Keywords: coronavirus; COVID-19; pandemic; model; partial unlock; social distancing; economic impact; ventilator utilization; SARS-CoV-2
Online: 15 April 2020 (10:02:51 CEST)
This paper analyzes the stability and usefulness of a human-in-the-loop caseload management method for COVID-19. This can control the balance between medical resource utilization and economic shutdown duration across significant scenario variation. It reduce the total cases by controlling the rate of spreading as groups cross the herd immunity threshold, and suggests late intervention has more effect on total cases than early intervention once containment has failed. Data as of April 11, 2020 show that “flattening” strategy for COVID-19 in both the world and the U.S. is working so well that a significantly effective removal of social distancing (aka “unlock”) at any time in the next few years, other than after widespread and effective vaccination, will produce a rebound overloading the healthcare system. For the world, by early April flattening was working so well that a world rebound could be projected in 2021 that would exceed in critical demand even the additional million or so ventilators requested by world governments. In the U.S., whose trajectory is somewhat ahead of the world, the projected rebound of a late year unlock is already greater than the current crisis projected peak. Most citizens are tacitly expecting much sooner rather than much later unlocks. Leaving economies locked down for a long time is its own catastrophe, especially for countries that cannot provide substantial economic aid to their citizens. An SIR-type model was used with clear parameters suitable for public information, and both tracking and predictive capabilities, and an additional simulation of a decision-maker on selected-day partial unlock designed mainly to manage ventilator or other critical resource utilization, to make sure they are neither idle nor over committed. Using certain days of the week, already practiced by some countries, is not a necessary part of the method, but was used in the simulation to give a highly quantified unlock scheme. It also helps restore economic activity. While the model shows total cumulative cases, and therefore deaths, declining initially with flattening, when flattening begins to produce large rebounds the death rate goes back up. Partial unlock to manage critical resources brings the cumulative cases down about 8-12% between now and the second half of 2021, and therefore saves lives with some degree of certainty.
REVIEW | doi:10.20944/preprints202004.0179.v2
Subject: Life Sciences, Virology Keywords: COVID-19; SARS-CoV-2; human coronavirus; control; vitamin D; antibiotic resistance; antimicrobial agents; BCG; malaria; climate; latitude
Online: 15 April 2020 (08:25:18 CEST)
Mankind faces a coronavirus pandemic originating from a seafood market in Wuhan, China since December 2019. The pathogen was named novel coronavirus (n-CoV) and bats are the identified key reservoir. The coronavirus disease 2019 (COVID-19) quickly spread over China across the globe, turned into a pandemic with exponentially increasing numbers of cases and significant mortality rate. China reacted with lockdowns and strict control measurements to prevent spreading the virus. The treatment of severe cases was hampered by lack of specific vaccines. Vaccine-development and production is a painstaking process and can only be enforced by international cooperation. Different supportive treatment options surfaced due to combinations of antiviral agents with antibiotic drugs. Elderly, male, immune-suppressed patients with co-morbidities showed a high mortality rate. Health literacy, strong immune system, adequate serum 25-hydroxyvitamin D (25(OH)D) concentrations and healthy life style choices can support fast recovery. Antibiotic resistance needs to be addressed by development of new generation antimicrobials against nosocomial infections in preparation for future outbreaks. Plant-biosynthesis of nanomaterials and antiseptics may help in prevention and recovery rate. Prevalence of COVID-19 maybe inversely related to BCG vaccination, endemicity of malaria, humidy and temperature but directly with latitude. Recommendations to prevent the spread of COVID-19 should be followed strictly.
Tue, 14 April 2020
Subject: Life Sciences, Virology Keywords: Dengue; COVID-19; SARS-CoV-2; epidemiology; infection; mortality; cross-protection; Dengue vaccine; ELISA; Dengvaxia
Online: 14 April 2020 (08:49:03 CEST)
We observed that global severity maps of ongoing dengue epidemic and COVID-19 pandemic do not overlap. Countries where dengue is highly endemic (>1.5 million cases/year) appear to be less hit by COVID-19 pandemic in terms of infection and transmission. Other evidences also support our proposition that pre-exposure to other wide-spread viral infections like dengue may thwart the spread of the COVID-19 pandemic.