Preprints on COVID-19 and SARS-CoV-2
Reminder: Please bear in mind that these are early stage research which have not gone through a rigorous peer review process, and should not be regarded as conclusive clinical guidance or be reported in news media as established fact.
REVIEW | doi:10.20944/preprints202004.0203.v4
Online: 2 November 2020 (10:18:00 CET)
The science around the use of masks by the general public to impede COVID-19 transmission is advancing rapidly. Policymakers need guidance on how masks should be used by the general population to combat the COVID-19 pandemic. In this narrative review, we develop an analytical framework to examine mask usage, considering and synthesizing the relevant literature to inform multiple areas: population impact; transmission characteristics; source control; PPE; sociological considerations; and implementation considerations. A primary route of transmission of COVID-19 is via respiratory droplets, and is known to be transmissible from presymptomatic and asymptomatic individuals. Reducing disease spread requires two things: first, limit contacts of infected individuals via physical distancing and other measures, and second, reduce the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces the transmissibility per contact by reducing transmission of infected droplets in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. The decreased transmissibility could substantially reduce the death toll and economic impact while the cost of the intervention is low. Given the current shortages of medical masks we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory droplets become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask-wearing by infectious people ("source control") with benefits at the population-level, rather than mask-wearing by susceptible people, such as health-care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation.
ARTICLE | doi:10.20944/preprints202007.0025.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: SARS-CoV-2; COVID-19; outpatients; treatment; zinc; hydroxychloroquine; azithromycin
Online: 3 July 2020 (08:52:22 CEST)
Objective: To describe outcomes of patients with coronavirus disease 2019 (COVID-19) in the outpatient setting after early treatment with zinc, low dose hydroxychloroquine, and azithromycin (the triple therapy) dependent on risk stratification. Design: Retrospective case series study. Setting: General practice. Participants: 141 COVID-19 patients with laboratory confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in the year 2020. Main Outcome Measures: Risk-stratified treatment decision, rate of hospitalization and all-cause death. Results: Of 335 positively PCR-tested COVID-19 patients, 127 were treated with the triple therapy. 104 of 127 met the defined risk stratification criteria and were included in the analysis. In addition, 37 treated and eligible patients who were confirmed by IgG tests were included in the treatment group (total N=141). 208 of the 335 patients did not meet the risk stratification criteria and were not treated. After 4 days (median, IQR 3-6, available for N=66/141) of onset of symptoms, 141 patients (median age 58 years, IQR 40-67; 73% male) got a prescription for the triple therapy for 5 days. Independent public reference data from 377 confirmed COVID-19 patients of the same community were used as untreated control. 4 of 141 treated patients (2.8%) were hospitalized, which was significantly less (p<0.001) compared with 58 of 377 untreated patients (15.4%) (odds ratio 0.16, 95% CI 0.06-0.5). Therefore, the odds of hospitalization of treated patients were 84% less than in the untreated group. One patient (0.7%) died in the treatment group versus 13 patients (3.5%) in the untreated group (odds ratio 0.2, 95% CI 0.03-1.5; p=0.16). There were no cardiac side effects. Conclusions: Risk stratification-based treatment of COVID-19 outpatients as early as possible after symptom onset with the used triple therapy, including the combination of zinc with low dose hydroxychloroquine, was associated with significantly less hospitalizations and 5 times less all-cause deaths.
ARTICLE | doi:10.20944/preprints202004.0315.v1
Subject: Life Sciences, Molecular Biology Keywords: COVID-19; SARS-CoV2; ACE2 receptor; medical cannabis; CBD
Online: 19 April 2020 (02:45:50 CEST)
With the rapidly growing pandemic of COVID-19 caused by the new and challenging to treat zoonotic SARS-CoV2 coronavirus, there is an urgent need for new therapies and prevention strategies that can help curtail disease spread and reduce mortality. Inhibition of viral entry and thereby spread constitute plausible therapeutic avenues. Similar to other respiratory pathogens, SARS-CoV2 is transmitted through respiratory droplets, with potential for aerosol and contact spread. It uses receptor-mediated entry into the human host via angiotensin-converting enzyme II (ACE2) that is expressed in lung tissue, as well as oral and nasal mucosa, kidney, testes, and the gastrointestinal tract. Modulation of ACE2 levels in these gateway tissues may prove a plausible strategy for decreasing disease susceptibility. Cannabis sativa, especially one high in the anti-inflammatory cannabinoid cannabidiol (CBD), has been proposed to modulate gene expression and inflammation and harbour anti-cancer and anti-inflammatory properties. Working under the Health Canada research license, we have developed over 800 new Cannabis sativa lines and extracts and hypothesized that high-CBD C. sativa extracts may be used to modulate ACE2 expression in COVID-19 target tissues. Screening C. sativa extracts using artificial human 3D models of oral, airway, and intestinal tissues, we identified 13 high CBD C. sativa extracts that modulate ACE2 gene expression and ACE2 protein levels. Our initial data suggest that some C. sativa extract down-regulate serine protease TMPRSS2, another critical protein required for SARS-CoV2 entry into host cells. While our most effective extracts require further large-scale validation, our study is crucial for the future analysis of the effects of medical cannabis on COVID-19. The extracts of our most successful and novel high CBD C. sativa lines, pending further investigation, may become a useful and safe addition to the treatment of COVID-19 as an adjunct therapy. They can be used to develop easy-to-use preventative treatments in the form of mouthwash and throat gargle products for both clinical and at-home use. Such products ought to be tested for their potential to decrease viral entry via the oral mucosa. Given the current dire and rapidly evolving epidemiological situation, every possible therapeutic opportunity and avenue must be considered.
REVIEW | doi:10.20944/preprints202003.0235.v2
Subject: Medicine & Pharmacology, Nutrition Keywords: acute respiratory distress syndrome (ARDS); ascorbic acid; cathelicidin; coronavirus; COVID-19; cytokine storm; influenza; observational; pneumonia, prevention; respiratory tract infection; solar radiation; treatment; UVB; vitamin C; vitamin D
Online: 30 March 2020 (05:48:43 CEST)
The world is in the grips of the COVID-19 pandemic. Public health measures that can reduce the risk of infection and death in addition to quarantines are desperately needed. This article reviews the roles of vitamin D in reducing risk of respiratory tract infections, knowledge about the epidemiology of influenza and COVID-19, and how vitamin D supplementation might be a useful measure to reduce risk. Through several mechanisms, vitamin D can reduce risk of infections. Those mechanisms include inducing cathelicidins and defensins that can lower viral replication rates and reducing concentrations of pro-inflammatory cytokines that produce the inflammation that injures the lining of the lungs, leading to pneumonia, as well as increase concentrations of anti-inflammatory cytokines. Several observational studies and clinical trials reported that vitamin D supplementation reduced risk of influenza, whereas others did not. Evidence supporting the role of vitamin D in reducing risk of COVID-19 includes that the outbreak occurred in winter, a time when 25-hydroxyvitamin D [25(OH)D] concentrations are lowest; that the number of cases in the Southern Hemisphere near the end of summer are low; that vitamin D deficiency has been found to contribute to acute respiratory distress syndrome, and that case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower 25(OH)D concentration. To reduce risk of infection, it is recommended that people at risk of influenza and/or COVID-19 consider taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d. The goal should be to raise 25(OH)D concentrations above 40–60 ng/ml (100–150 nmol/l). For treatment of people who become infected with COVID-19, higher vitamin D3 doses might be useful. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations.
ARTICLE | doi:10.20944/preprints202005.0057.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; treatment; drug; survival; antiviral; hydroxychloroquine
Online: 9 May 2020 (04:45:37 CEST)
Background: Although no specific treatment for COVID 19 has been proven effective yet, some drugs with in vitro potential against SARS-CoV-2 virus have been proposed for clinical use. Hydroxychloroquine has in vitro anti-viral and immunomodulatory activity, but there is no current clinical evidence of its effectiveness on the outcome of the disease. Methods: We enrolled all 18-85 years old inpatients from Central Defense Hospital, Madrid, Spain, who were hospitalised due to COVID-19 and had a definitive outcome (either dead or discharged). We used a statistical survival analysis. Results: We analysed 220 medical records. 166 patients met the inclusion criteria. 48,8 % of patients not treated with HCQ died, versus 22% in the group of hydroxychloroquine (p=0,002). According to clinical picture at admission, hydroxychloroquine increased the mean cumulative survival in all groups from 1,4 to 1,8 times. This difference was statistically significant in the mild group. Conclusions: in a cohort of 166 patients between 18 to 85 years hospitalised with COVID-19, hydroxychloroquine treatment with an initial loading dose of 800mg improved patient survival when admitted in early stages of the disease. There was a non-statistically significant trend towards survival in all groups, which will need to be clarified in subsequent studies.
HYPOTHESIS | doi:10.20944/preprints202004.0023.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; bradykinin; ACE2; pulmonary angioedema; ARDS; icatibant
Online: 3 April 2020 (04:13:43 CEST)
Most striking observations in COVID-19 patients are the hints on pulmonary edema (also seen on CT scans as ground glass opacities), dry cough, fluid restrictions to prevent more severe hypoxia, the huge PEEP that is needed while lungs are compliant, and the fact that anti-inflammatory therapies are not powerful enough to counter the severity of the disease. We propose that the severity of the disease and many deaths are due to a local vascular problem due to activation of B1 receptors on endothelial cells in the lungs. SARS-CoV-2 enters the cell via ACE2, a cell membrane bound molecule with enzymatic activity that next to its role in RAS is needed to inactivate des-Arg9 bradykinin, the potent ligand of the bradykinin receptor type 1 (B1). In contrast to bradykinin receptor 2 (B2), the B1 receptor on endothelial cells is upregulated by proinflammatory cytokines. Without ACE2 acting as a guardian to inactivate the ligands of B1, the lung environment is prone for local vascular leakage leading to angioedema. Angioedema is likely a feature already early in disease, and might explain the typical CT scans and the feeling of people that they drown. In some patients, this is followed by a clinical worsening of disease around day 9 due to the formation antibodies directed against the spike (S)-antigen of the corona-virus that binds to ACE2 that could contribute to disease by enhancement of local immune cell influx and proinflammatory cytokines leading to damage. In parallel, inflammation induces more B1 expression, and possibly via antibody-dependent enhancement of viral infection leading to continued ACE2 dysfunction in the lung because of persistence of the virus. In this viewpoint we propose that a bradykinin-dependent local lung angioedema via B1 and B2 receptors is an important feature of COVID-19, resulting in a very high number of ICU admissions. We propose that blocking the B1 and B2 receptors might have an ameliorating effect on disease caused by COVID-19. This kinin-dependent pulmonary edema is resistant to corticosteroids or adrenaline and should be targeted as long as the virus is present. In addition, this pathway might indirectly be responsive to anti-inflammatory agents or neutralizing strategies for the anti-S-antibody induced effects, but by itself is likely to be insufficient to reverse all the pulmonary edema. Moreover, we provide a suggestion of how to ventilate in the ICU in the context of this hypothesis.
ARTICLE | doi:10.20944/preprints202003.0226.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: COVID-2019; Mpro; 6LU7; medicinal plant compounds; docking
Online: 13 March 2020 (03:19:02 CET)
COVID-19, a new strain of coronavirus (CoV), was identified in Wuhan, China, in 2019. No specific therapies are available and investigations regarding COVID-19 treatment are lacking. Liu et al. (2020) successfully crystallised the COVID-19 main protease (Mpro), which is a potential drug target. The present study aimed to assess bioactive compounds found in medicinal plants as potential COVID-19 Mpro inhibitors, using a molecular docking study. Molecular docking was performed using Autodock 4.2, with the Lamarckian Genetic Algorithm, to analyse the probability of docking. COVID-19 Mpro was docked with several compounds, and docking was analysed by Autodock 4.2, Pymol version 18.104.22.168 Edu, and Biovia Discovery Studio 4.5. Nelfinavir and lopinavir were used as standards for comparison. The binding energies obtained from the docking of 6LU7 with native ligand, nelfinavir, lopinavir, kaempferol, quercetin, luteolin-7-glucoside, demethoxycurcumin, naringenin, apigenin-7-glucoside, oleuropein, curcumin, catechin, epicatechin-gallate, zingerol, gingerol, and allicin were -8.37, -10.72, -9.41, -8.58, -8.47, -8.17, -7.99, -7.89, -7.83, -7.31, -7.05, -7.24, -6.67, -5.40, -5.38, and -4.03 kcal/mol, respectively. Therefore, nelfinavir and lopinavir may represent potential treatment options, and kaempferol, quercetin, luteolin-7-glucoside, demethoxycurcumin, naringenin, apigenin-7-glucoside, oleuropein, curcumin, catechin, and epicatechin-gallate appeared to have the best potential to act as COVID-19 Mpro inhibitors. However, further research is necessary to investigate their potential medicinal use.
REVIEW | doi:10.20944/preprints202010.0330.v2
Subject: Medicine & Pharmacology, Allergology Keywords: COVID-19; Public Health; Lockdowns; Cost-benefit analysis; Groupthink
Online: 4 November 2020 (10:14:33 CET)
The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused the Coronavirus Disease 2019 (COVID-19) worldwide pandemic in 2020. In response, most countries in the world implemented lockdowns, restricting their population’s movements, work, education, gatherings, and general activities in attempt to ‘flatten the curve’ of COVID-19 cases. The public health goal of lockdowns was to save the population from COVID-19 cases and deaths, and to prevent overwhelming health care systems with COVID-19 patients. In this narrative review I explain why I changed my mind about supporting lockdowns. First, I explain how the initial modeling predictions induced fear and crowd-effects [i.e., groupthink]. Second, I summarize important information that has emerged relevant to the modeling, including about infection fatality rate, high-risk groups, herd immunity thresholds, and exit strategies. Third, I describe how reality started sinking in, with information on significant collateral damage due to the response to the pandemic, and information placing the number of deaths in context and perspective. Fourth, I present a cost-benefit analysis of the response to COVID-19 that finds lockdowns are far more harmful to public health than COVID-19 can be. Controversies and objections about the main points made are considered and addressed. I close with some suggestions for moving forward.
ARTICLE | doi:10.20944/preprints202003.0455.v1
Online: 31 March 2020 (10:16:13 CEST)
Background: COVID-19, a member of corona virus family is spreading its tentacles across the world due to lack of drugs at present. Associated with its infection are cough, fever and respiratory problems causes more than 15% mortality worldwide. It is caused by a positive, single stranded RNA virus from the enveloped coronaviruse family. However, the main viral proteinase (Mpro/3CLpro) has recently been regarded as a suitable target for drug design against SARS infection due to its vital role in polyproteins processing necessary for coronavirus reproduction.Objectives: The present in silico study was designed to evaluate the effect of Eucalyptol (1,8 cineole), a essential oil component from eucalyptus oil, on Mpro by docking study.Methods: In the present study, molecular docking studies were conducted by using 1-click dock and swiss dock tools. Protein interaction mode was calculated by Protein Interactions Calculator.Results: The calculated parameters such as RMSD, binding energy, and binding site similarity indicated effective binding of eucalyptol to COVID-19 proteinase. Active site prediction further validated the role of active site residues in ligand binding. PIC results indicated that, Mpro/eucalyptol complexes forms hydrophobic interactions, hydrogen bond interactions and strong ionic interactions.Conclusions: Therefore, eucalyptol may represent potential treatment potential to act as COVID-19 Mpro inhibitor. However, further research is necessary to investigate their potential medicinal use.
ARTICLE | doi:10.20944/preprints202003.0422.v1
Online: 29 March 2020 (06:16:20 CEST)
Currently, the world is struggling with the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Prion-like domains are critical for virulence and the development of therapeutic targets; however, the prion-like domains in the SARS-CoV-2 proteome have not been analyzed. In this in silico study, using the PLAAC algorithm, we identified the presence of prion-like domains in the SARS-CoV-2 spike protein. Compared with other viruses, a striking difference was observed in the distribution of prion-like domains in the spike protein, since SARS-CoV-2 was the only coronavirus with a prion-like domain found in the receptor-binding domain of the S1 region of the spike protein. The presence and unique distribution of prion-like domains in the SARS-CoV-2 receptor-binding domains of the spike protein is particularly interesting, since although the SARS-CoV-2 and SARS-CoV S proteins share the same host cell receptor, angiotensin-converting enzyme 2 (ACE2), SARS-CoV-2 demonstrates a 10- to 20-fold higher affinity for ACE2. Finally, we identified prion-like domains in the α1 helix of the ACE2 receptor that interact with the viral receptor-binding domain of SARS-CoV-2. Taken together, the present findings indicate that the identified PrDs in the SARS-CoV-2 receptor-binding domain (RBD) and ACE2 region that interact with RBD have important functional roles in viral adhesion and entry.
ARTICLE | doi:10.20944/preprints202002.0179.v1
Online: 14 February 2020 (02:34:55 CET)
Ongoing outbreak of pneumonia caused by novel coronavirus (2019-nCoV) began in December 2019 in Wuhan, China, and the number of new patients continues to increase. On the contrary to ongoing outbreak in China, however, there are limited secondary outbreaks caused by exported case outside the country. We here conducted simulations to estimate the impact of potential secondary outbreaks at a community outside China. Simulations using stochastic SEIR model was conducted, assuming one patient was imported to a community. Among 45 possible scenarios we prepared, the worst scenario resulted in total number of persons recovered or removed to be 997 (95% CrI 990-1,000) at day 100 and maximum number of symptomatic infectious patients per day of 335 (95% CrI 232-478). Calculated mean basic reproductive number (R0) was 6.5 (Interquartile range, IQR 5.6-7.2). However, with good case scenarios with different parameter led to no secondary case. Altering parameters, especially time to hospital visit could change the impact of secondary outbreak. With this multiple scenarios with different parameters, healthcare professionals might be able to prepare for this viral infection better.
Subject: Medicine & Pharmacology, Allergology Keywords: antibodies; COVID-19; glycans; immunoglobulin M; SARS-CoV-2; pneumonia; prediction; protection
Online: 24 April 2020 (10:25:27 CEST)
The natural history of COVID-19 caused by SARS-CoV-2 is extremely variable, ranging from asymptomatic infection, to pneumonia, and to complications eventually fatal. We propose here the first model, explaining how the outcome of first, crucial 10-15 days after infection, hangs on the balance between the cumulative dose of viral exposure and the efficacy of the local innate immune response (natural IgA and IgM antibodies, MBL). If SARS-CoV-2 runs the blockade of this innate immunity and spreads from the upper airways to the alveoli in the early phases of the infections, it can replicate with no local resistance, causing pneumonia and releasing high amounts of antigens. The delayed and strong adaptive immune response (high affinity IgM and IgG antibodies) that follows, causes severe inflammation and triggers mediator cascades (complement, coagulation, and cytokine storm) leading to complications often requiring intensive therapy and being, in some patients, fatal. Strenuous exercise and high flow air in the incubation days and early stages of COVID-19, facilitates direct penetration of the virus to the lower airways and the alveoli, without impacting on the airway’s mucosae covered by neutralizing antibodies. This allows the virus to bypass the efficient immune barrier of the upper airways mucosa in young and healthy athletes. In conclusion, whether the virus or the adaptative immune response reach the lungs first, is a crucial factor deciding the fate of the patient. This “quantitative and time-sequence dependent” model has several implications for prevention, diagnosis, and therapy of COVID-19.
Online: 27 January 2021 (15:08:12 CET)
To date, uncertainty remains about how long the protective immune responses against SARS-CoV-2 persists and reports of suspected reinfection began to be described in recovered patients months after the first episode. Viral evolution may favor reinfections, and the recently described spike mutations, particularly in the receptor binding domain (RBD) in SARS-CoV-2 lineages circulating in the UK, South Africa, and most recently in Brazil, have raised concern on their potential impact in infectivity, immune escape and reinfection. We report a case of reinfection from distinct SARS-CoV-2 lineages presenting the E484K mutation in Brazil, a variant associated with escape from neutralizing antibodies.
ARTICLE | doi:10.20944/preprints202005.0486.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; SARS-CoV-2; azithromycin; hydroxychloroquine; primary care
Online: 31 May 2020 (17:51:52 CEST)
The challenge regarding COVID-19 is to prevent complications and fatal evolution. Azithromycin (AZM) and hydroxychloroquine (HCQ) have proven their antiviral effect in vitro. We aimed to assess the efficacy and safety of AZM alone or combined to HCQ, prescribed, at an early stage, in patients with Covid-19, in a primary care setting. Eighty-eight patients received either no or a symptomatic treatment (NST) (n=34) or AZM alone (n=34) or AZM+HCQ (n=20). The efficacy end point was the time to clinical recovery and the safety end point was the occurrence of cardiovascular events. The mean (SD) times to achieve clinical recovery were respectively 25.8 days (11.1), 12.9 days (13.4) and 9.2 days (9.3), showing a statistically significant difference between NST and AZM alone (p<0.0001) or AZM+HCQ (p<0.0001). To improve the evidence level, a case-control analysis was performed on a sample of 57 patients (19/group) matched for age, sex and BMI. The statistical difference between NST and AZM was confirmed (p=0.0149) as well as the difference with AZM+HCQ (p=0.0002). No cardiac toxicity was recorded in any patient. No statistical difference was shown between AZM and AZM+HCQ groups, although the dual therapy tended to be more effective in patients over 50 years, based on an analysis using the cox model. In conclusion, AZM and AZM+HCQ favourably impacted the course of the disease. We need trials, ideally prospective/double blind, to show if a statistical difference can be evidenced with a broader group, and clarify the indications of each treatment depending on initial clinical presentation.
ARTICLE | doi:10.20944/preprints202004.0457.v2
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Covid-19; desmosine; dp-ucMGP; elastic fibers; factor II; matrix Gla protein; PIVKA-II; protein S; vitamin K; vitamin K antagonist
Online: 29 May 2020 (04:16:20 CEST)
Background: A significant proportion of SARS-CoV-2-infected patients develops respiratory failure. Thromboembolism is also prevalent in coronavirus disease 2019 (Covid-19). Vitamin K plays a role in coagulation and possibly also in lung diseases. We therefore hypothesized that vitamin K is implicated in Covid-19 pathogenesis. Methods: 134 Covid-19 patients and 184 controls were included. Inactive vitamin K-dependent matrix Gla protein (i.e.dp-ucMGP) and prothrombin (i.e. PIVKA-II) were measured, which are inversely related to respectively extrahepatic and hepatic vitamin K status. Desmosine was measured to quantify elastic fiber degradation. Lung involvement and arterial calcifications severity were assessed by computed tomography. Results Dp-ucMGP was elevated in Covid-19 patients compared to controls (P=0.001). Higher dp-ucMGP was found in Covid-19 patients with poor compared to better outcomes (P=0.002). PIVKA-II was normal in 81.8%, mildly elevated in 14.0% and moderately elevated in 4.1% of Covid-19 patients not using vitamin K antagonists. Dp-ucMGP in Covid-19 patients was correlated with desmosine (P<0.001), thoracic aortic calcification (P<0.001) but not with pneumonia severity. Conclusions: Extrahepatic vitamin K status was severely reduced in Covid-19 patients, as reflected by elevated inactive MGP, and related to poor outcome. Procoagulant prothrombin activity remained preserved in the majority of Covid-19 patients, which is compatible with the increased thrombogenicity that is frequently observed in severe Covid-19. Impaired MGP activation was linked to accelerated elastic fiber degradation and premorbid vascular calcifications. A trial should assess whether increasing MGP and protein S activity by vitamin K administration improves Covid-19 outcomes.
HYPOTHESIS | doi:10.20944/preprints202004.0124.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; SARS-CoV-2; Therapy; Chloroquine; Hydroxychloroquine; Zinc
Online: 8 April 2020 (10:54:33 CEST)
Currently, drug repurposing is an alternative to novel drug development for the treatment of COVID-19 patients. The antimalarial drug chloroquine (CQ) and its metabolite hydroxychloroquine (HCQ) are currently being tested in several clinical studies as potential candidates to limit SARS-CoV-2-mediated morbidity and mortality. CQ and HCQ (CQ/HCQ) inhibit pH-dependent steps of SARS-CoV-2 replication by increasing pH in intracellular vesicles and interfere with virus particle delivery into host cells. Besides direct antiviral effects, CQ/HCQ specifically target extracellular zinc to intracellular lysosomes where it interferes with RNA-dependent RNA polymerase activity and coronavirus replication. As zinc deficiency frequently occurs in elderly patients and in those with cardiovascular disease, chronic pulmonary disease, or diabetes, we hypothesize that CQ/HCQ plus zinc supplementation may be more effective in reducing COVID-19 morbidity and mortality than CQ or HCQ in monotherapy. Therefore, CQ/HCQ in combination with zinc should be considered as additional study arm for COVID-19 clinical trials.
Subject: Life Sciences, Virology Keywords: COVID-19; coronavirus; fulminant myocarditis; infection; echocardiography.
Online: 7 April 2020 (01:03:22 CEST)
Background: Coronavirus Disease 2019 (COVID-19) has been demonstrated to be the cause of pneumonia. Nevertheless, it has not been reported as the cause of acute myocarditis or fulminant myocarditis. Case presentation: A 63-year-old male was admitted with pneumonia and cardiac symptoms. He was genetically confirmed as having COVID-19 according to sputum testing on the day of admission. He also had elevated troponin I (Trop I) level (up to 11.37 g/L) and diffuse myocardial dyskinesia along with a decreased left ventricular ejection fraction (LVEF) on echocardiography. The highest level of interleukin-6 was 272.40 pg/ml. Bedside chest radiographs showed typical ground-glass changes indicative of viral pneumonia. Laboratory test results for viruses that cause myocarditis were all negative. The patient conformed to the diagnostic criteria of the Chinese expert consensus statement for fulminant myocarditis. After receiving antiviral therapy and mechanical life support, Trop I was reduced to 0.10 g/L, and interleukin-6 was reduced to 7.63 pg/ml. Moreover, the LVEF of the patient gradually recovered to 68%. The patient died of aggravation of secondary infection on the 33rd day of hospitalization. Conclusion: COVID-19 patients may develop severe cardiac complications such as myocarditis and heart failure. This is the first report of COVID-19 complicated with fulminant myocarditis. The mechanism of cardiac pathology caused by COVID-19 needs further study.
Subject: Life Sciences, Immunology Keywords: 2019-nCoV; coronavirus; peptide vaccine; CD4+ epitope; CD8+ epitope
Online: 8 February 2020 (05:56:31 CET)
In this report, we demonstrate that it is possible to design epitope-based peptide vaccine candidates to counteract the novel China coronavirus (2019-nCoV) by using an approach similar to the one used in cancer neoantigen vaccination therapy. We identified multiepitope peptide vaccine candidates against 2019-nCov that can potentially trigger both CD4+ and CD8+ T cell immune response with increased efficiency due to the presence of CD4+ and CD8+ T cell epitopes and a cathepsin-sensitive linker. Furthermore, we suggest that the peptide design strategy should incorporate population-specific HLA alleles in order to optimize binding specificity of the peptides. We refer to this as populationalized vaccinomics.
ARTICLE | doi:10.20944/preprints202003.0333.v1
Online: 23 March 2020 (04:30:47 CET)
COVID-19, a rapidly spreading new strain of coronavirus, has affected more than 150 countries and received worldwide attention. The lack of efficacious drugs or vaccines against SARS-CoV-2 has further worsened the situation. Thus, there is an urgent need to boost up research for the development of effective therapeutics and affordable diagnostic against COVID-19. The crystallized form of SARS-CoV-2 main protease (Mpro) was demonstrated by a Chinese researcher Liu et al. (2020) which is a novel therapeutic drug target. This study was conducted to evaluate the efficacy of medicinal plant-based bioactive compounds against COVID-19 Mpro by molecular docking study. Molecular docking investigations were performed by using Molegro Virtual Docker 7 to analyze the inhibition probability of these compounds against COVID-19. COVID-19 Mpro was docked with 80 flavonoid compounds and the binding energies were obtained from the docking of (PDB ID: 6LU7: Resolution 2.16 Å) with the native ligand. According to obtained results, hesperidin, rutin, diosmin, apiin, diacetylcurcumin, (E)-1-(2-Hydroxy-4-methoxyphenyl)-3-[3-[(E)-3-(2-hydroxy-4- methoxyphenyl)-3-oxoprop-1-enyl]phenyl]prop-2-en-1-one, and beta,beta'-(4-Methoxy-1,3- phenylene)bis(2'-hydroxy-4',6'-dimethoxyacrylophenone have been found as more effective on COVID-19 than nelfinavir. So, this study will pave a way for doing advanced experimental research to evaluate the real medicinal potential of these compounds to cure COVID-19.
ARTICLE | doi:10.20944/preprints202004.0058.v1
Subject: Medicine & Pharmacology, Other Keywords: coronavirus disease 2019 (COVID-19); school closure; time series analysis; Japan
Online: 6 April 2020 (13:11:12 CEST)
Background: Coronavirus disease 2019 (COVID-19) pandemic are causing significant damages to many nations. For mitigating its risk, Japan’s Prime Minister called on all elementary, junior high and high schools nationwide to close beginning March 1, 2020. However, its effectiveness in decreasing disease burden has not been investigated. Methods: We used daily data on the report of COVID-19 and coronavirus infection incidence in Japan until March 31, 2020. Time series analysis were conducted using Bayesian method. Local linear trend models with interventional effect were constructed for number of newly reported cases of COVID-19, including asymptomatic infections. We considered that the effects of intervention start to appear 9 days after the school closure; i.e., on March 9. Results: The intervention of school closure did not appear to decrease the incidence of coronavirus infection. If the effectiveness of school closure began on March 9, mean coefficient α for effectiveness of the measure was calculated to be 0.08 (95% credible interval -0.36 to 0.65), and the actual reported cases were more than predicted, yet with rather wide credible interval. Sensitivity analyses using different dates also showed similar results. Conclusions: School closure carried out in Japan did not show the effectiveness to mitigate the transmission of novel coronavirus infection.
ARTICLE | doi:10.20944/preprints202003.0078.v1
Online: 5 March 2020 (03:15:43 CET)
Background: Cigarette smoking (CS) is a global public health problem and a high-risk factor for various diseases. In December 2019, a novel coronavirus (HCoV-19) was identified in Wuhan, China. Because ACE2 has been identified as a receptor for HCoV-19, we hypothesize that CS affects the expression pattern of ACE2 in respiratory tract, causing differences in susceptibility to the virus. Methods: Three datasets (GSE994, GSE17913, and GSE18344), were downloaded from the Gene Expression Omnibus (GEO) database. Correlation and enrichment analysis were used to evaluate the function of ACE2. Also, the different expression of ACE2 in different groups of three datasets were analyzed. Results: Genes associated with ACE2 were enriched in important biological processes such as viral processes and immune response. Elevated ACE2 were found in intrapulmonary airways (GSE994) and oral epithelial cells (GSE17913) of smokers but not those of non-smokers or former smokers. Significant dose- and time-dependent relationships between CS and ACE2 expression were observed in mouse lung tissues, and long periods without smoking were found to significantly reduce ACE2 expression. Conclusions: Both human and rat data confirmed that CS could induce increased ACE2 in the respiratory tract, indicating that smokers have a higher susceptibility to HCoV-19.
ARTICLE | doi:10.20944/preprints202103.0271.v1
Online: 9 March 2021 (12:37:24 CET)
Background The World Health Organization has recently recognized Long COVID, calling the international medical community to strengthen research and comprehensive care of patients with this condition. However, if Long COVID pertains to children as well is not yet clear. Methods An anonymous, online survey was developed by an organization of parents of children suffering from persisting symptoms since initial infection. Parents were asked to report signs and symptoms, physical activity and mental health issues. Only children with symptoms persisting for more than four weeks were included. Results 510 children were included (56.3% females) infected between January 2020 and January 2021. At their initial COVID-19 infection, 22 (4.3%) children were hospitalized. Overall, children had persisting COVID-19 for a mean of 8.2 months (SD 3.9). Most frequent symptoms were: Tiredness and weakness (444 patients, 87.1% of sample), Fatigue (410, 80.4%), Headache (401, 78.6%), Abdominal pain (387, 75.9%), Muscle and joint pain (309, 60.6%), Post-exertional malaise (274, 53.7%), rash (267, 52.4%). 484 (94.9%) children had had at least four symptoms. 129 (25.3%) children have suffered constant COVID-19 infection symptoms, 252 (49.4%) have had periods of apparent recovery and then symptoms returning, and 97 (19.0%) had a prolonged period of wellness followed by symptoms. Only 51 (10.0%) children have returned to previous levels of physical activity. Parents reported a significant prevalence of Neuropsychiatric symptoms. Conclusions Our study provides further evidence on Long COVID in children. Symptoms like fatigue, headache, muscle and joint pain, rashes and heart palpitations, and mental health issues like lack of concentration and short memory problems, were particularly frequent and confirm previous observations, suggesting that they may characterize this condition. A better comprehension of Long COVID is urgently needed..
ARTICLE | doi:10.20944/preprints202002.0408.v1
Subject: Life Sciences, Microbiology Keywords: Wuhan SARS-CoV-2; ACE2; DC-SIGN; L-SIGN; expression; susceptibility; race; age; gender; smoking; single cell
Online: 27 February 2020 (12:45:26 CET)
The current spreading novel coronavirus SARS-CoV-2 is highly infectious and pathogenic and has attracted global attention. Recent studies have found that SARS-CoV-2 and SARS-CoV share around 80% of homology and use the same cell entry receptor, ACE2. These inspired us to study other receptors of SARS-CoV, which may be used for SARS-CoV-2 binding as well. In this study, we screened the gene expression of three receptors (ACE2, DC-SIGN and L-SIGN) in four datasets of normal lung tissue from lung adenocarcinoma patients and two single-cell RNA sequencing datasets from normal lung and bronchial epithelial cells separately. No significant difference in gene expression of these three receptors were found between gender groups (male vs female). We found higher gene expression of DC-SIGN in elder with age>60 and higher gene expression of L-SIGN in Caucasian than Asian. Similar to ACE2, we observed significantly higher DC-SIGN gene expression in the lungs of smokers, especially former smokers. However, smokers upregulate ACE2 and DC-SIGN gene expression in different cell types. In the whole lung, ACE2 is actively expressed in remodeled Alveolar Type II cells of former smokers, while DC-SIGN is largely expressed in monocytes of former smokers and dendritic cells of current smokers. In bronchial epithelium, no obvious gene expression of DC-SIGN and L-SIGN was observed while ACE2 was found to be actively expressed in goblet cells of current smokers and club cells of non-smokers. In conclusion, our findings may indicate that smokers, especially former smokers, and people over 60 have higher risk and are more susceptible to SARS-CoV-2 infection. Also, this study provides hints on possible SARS-CoV-2 pathogenicity mechanisms in lung infection.
ARTICLE | doi:10.20944/preprints202003.0214.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: SARS-Cov-2; Citrus sp.; Galangal; Curcuma sp.; Sappan wood
Online: 12 March 2020 (13:59:40 CET)
COVID-19 pandemic is a serious problem in the world today. The SARS-CoV-2 virus that causes COVID-19 has important proteins used for its infection and development, namely the protease and spike glycoprotein. The RBD (Receptor Binding Domain) of spike glycoprotein (RBD-S) can bind to the ACE2 (Angiotensin Converting Enzyme-2) receptor at the protease domain (PD) (PD-ACE2) of the host cell, thereby leading to a viral infection. This study aims to reveal the potential of compounds contained in Curcuma sp., Citrus sp., Alpinia galanga, and Caesalpinia sappan as anti SARS-CoV-2 through its binding to 3 protein receptors. The study was conducted by molecular docking using the MOE 2010 program (licensed from Faculty of Pharmacy UGM, Indonesia). The selected protein targets are RBD-S (PDB ID:6LXT), PD-ACE2 (PDB ID: 6VW1), and SARS-CoV-2 protease (PDB ID:6LU7). The affinities of bonds formed is represented as a docking score. The results show that hesperidin, one of the compounds in Citrus sp., has the lowest docking score for all three protein receptors representing the highest affinity to bind the receptors. Moreover, all of the citrus flavonoids possess good affinity to the respected receptors as well as curcumin, brazilin, and galangin, indicating that those compounds perform inhibitory potential for the viral infection and replication. In general, the results of this study indicate that Citrus sp. exhibit the best potential as an inhibitor to the development of the SARS-CoV-2, followed by galangal, sappan wood, and Curcuma sp. that can be consumed in daily life as prophylaxis of COVID-19.
ARTICLE | doi:10.20944/preprints202002.0315.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: COVID-19; adipose tissue; cancer; ACE2
Online: 23 February 2020 (10:30:06 CET)
The spread of 2019 novel coronavirus disease (COVID-19) throughout the world has been a severe challenge for public health. The human angiotensin-converting enzyme 2 (ACE2) has a remarkably high affinity binding to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). By the search for network database and re-analysis of pubic data, we found the level of ACE2 expression in adipose tissue was higher than that in lung tissue, which indicated the adipose tissue might be vulnerable to SARS-CoV-2 as well; the levels of ACE2 expressed by adipocytes and adipose progenitor cells were similar between non-obese individuals and obese individuals, but obese individuals have more adiposes so as to increase the number of ACE2-expressing cells; the expression of ACE2 in tumor tissues posed by five different types of cancers increased significantly compared with that in adjacent tissues. Thus, we suggest that more attentions might be given to obese individuals and the five types of cancer patients during the outbreak of COVID-19.
HYPOTHESIS | doi:10.20944/preprints202003.0279.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: chloroquine; COVID-19; SARS-CoV2; antiviral; viral prophylaxis
Online: 17 March 2020 (15:57:38 CET)
The novel coronavirus 2019 (COVID-19) pandemic is rapidly advancing despite public health measures. Pharmaceutical prophylaxis is an established approach to potentially control infectious diseases and is one solution to the urgent public health challenge posed by COVID-19. Screening and development of new vaccines and antivirals is expensive and time consuming while the repositioning of available drugs should receive priority attention as well as international government and agency support. Here we propose an old drug chloroquine (CQ) to be urgently repositioned as an ideal antiviral prophylactic against COVID-19. CQ has ability to block viral attachment and entry to host cells. Its proven clinical efficacy against a variety of viruses including COVID-19 and its current deployment in COVID-19 therapeutic trials strengthens its potential candidacy as a prophylactic. Furthermore, CQ has a long safety record, is inexpensive and widely available. Here we reviewed CQ's antiviral mechanisms, its laboratory efficacy activity against COVID-19, as well as CQ's pharmacokinetics in its established use against malaria and autoimmune diseases to recommend safe and potentially efficacious dose regimens for protection against COVID-19: a pre-exposure prophylaxis of 250-500mg daily and post-exposure prophylaxis at 8mg/kg/day for 3 days. We recommend further urgent research on CQ for COVID-19 prevention and urge that the above regimens be investigated in parallel with mass deployment by relevant agencies in attempts to contain the pandemic without unnecessary regulatory delays as benefits far outweigh risks or costs.
Online: 25 February 2020 (11:38:47 CET)
Background: Coronavirus disease 2019 (COVID-19) is a new viral respiratory disease and whether pregnant women are at increased risk of infection is unknown. Viral pneumonia is an important indirect cause of maternal death. Little is known about the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy. Objective: To describe the clinical characteristics of COVID-19 in pregnancy and their newborn infant, and we sought to explored whether the SARS-CoV-2 can be intrauterine vertically transmitted. Study Design: The study was a case series study conducted in the obstetric ward of Tongji Hospital affiliated to Huazhong University of science and technology, Wuhan, China. Demographic, clinical, laboratory and radiological profiles of the SARS-CoV-2 infection case series. A systematic testing procedure for SARS-CoV-2 infection using oropharyngeal swab, placenta tissue, vaginal mucus, and breast milk of mothers. and oropharyngeal swab, umbilical cord blood, and serum of newborns was conducted. Results: We have conducted the most thorough virological assessment to date, and we include a longer clinical observation in mother-infant dyads during hospitalization. The clinical course and outcomes of three pregnant women who acquired SARS-CoV-2 infection late pregnancy are described in mother-infant dyads. Two had caesarean delivery in their third trimester. All patients showed an uneventful perinatal course, and a successful outcome. No infants became infected by vertical transmission or during delivery. Conclusion: No evidence to suggest the potential risk of intrauterine vertical transmission in the case series and further in-depth study is needed. Both the pregnancy woman and infant showed fewer adverse maternal and neonatal outcomes.
COMMUNICATION | doi:10.20944/preprints202005.0126.v1
Online: 7 May 2020 (13:20:42 CEST)
Evidence for the potential for airborne transmission of SARS-CoV-19 continues to accumulate, with important implications for healthcare workers, as well as the general public. Three lines of evidence support this conclusion.
REVIEW | doi:10.20944/preprints202004.0548.v1
Subject: Keywords: COVID-19; coronavirus; SARS-CoV-2; aging; immunosenescence; inflammaging; inflammation; cytokine storm; epigenetics; biological clock; sirtuin; glycome
Online: 30 April 2020 (22:38:53 CEST)
The severity and outcome of coronavirus disease 2019 (COVID-19) largely depends on a patient’s age. Over 80% of hospitalizations are of those over 65 years of age with a 23-fold greater risk of death. In the clinic, COVID-19 patients most commonly present with fever, cough and dyspnea. Particularly in those over 65, it can progress to pneumonia, lung consolidation, cytokine release syndrome, endotheliitis, coagulopathy, multiple organ failure and death. Comorbidities such as cardiovascular disease, diabetes, obesity and hypertension increase the chances of fatal disease, but they alone do not explain the variability in COVID-19 symptoms. Here, we present the molecular differences between the young, middle-aged and elderly that may determine whether COVID-19 is a mild or life-threatening illness. We also discuss several biological age clocks that could be used in conjunction with genetic tests to identify both the mechanisms of the disease and individuals most at risk. Finally, based on these mechanisms, we discuss treatments that could increase survival in the elderly, not simply by inhibiting the virus, but by restoring patients’ ability to clear the infection.
ARTICLE | doi:10.20944/preprints202002.0299.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: SARS-CoV-2; infection; scRNA-Seq; ACE2; spermatogonia
Online: 21 February 2020 (02:42:15 CET)
In December 2019, a novel coronavirus (SARS-CoV-2) was identified in patients with pneumonia (called COVID-19) in Wuhan, Hubei Province, China. SARS-CoV-2 shares high sequence similarity and uses the same cell entry receptor, angiotensin-converting enzyme 2 (ACE2), as does severe acute respiratory syndrome coronavirus (SARS-CoV). Several studies have provided bioinformatic evidence of potential routes for SARS-CoV-2 infection in respiratory, cardiovascular, digestive and urinary systems. However, whether the reproductive system is a potential target of SARS-CoV-2 infection has not been determined. Here, we investigate the expression pattern of ACE2 in adult human testis at the level of single-cell transcriptomes. The results indicate that ACE2 is predominantly enriched in spermatogonia, Leydig and Sertoli cells. Gene ontology analyses indicate that GO categories associated with viral reproduction and transmission are highly enriched in ACE2-positive spermatogonia while male gamete generation related terms are down-regulated. Cell-cell junction and immunity related GO terms are increased in ACE2-positive Leydig and Sertoli cells, but mitochondria and reproduction related GO terms are decreased. These findings provide evidence that human testes are a potential target of SARS-CoV-2 infection which may have significant impact on our understanding of the pathophysiology of this rapidly spreading disease.
HYPOTHESIS | doi:10.20944/preprints202004.0349.v1
Subject: Keywords: Novel Coronavirus; respiratory distress; Favipiravir; statistics; correlation; beta thalassemia; immunisation; Italy; Sardinia; regression; heme
Online: 19 April 2020 (13:48:56 CEST)
The novel coronavirus pneumonia (COVID-19) is a contagious acute respiratory infectious disease whose causative agent has been demonstrated to be a novel virus of the coronavirus family, SARSCoV-2. A recent pre-print study has showed a heme attack on the 1-beta chain of hemoglobin by COVID19. Beta-thalassemia results of a default in the hemoglobin beta- chain synthesis. 1,5% global population are heterozygotes for this disease. In this study, by a multiple linear regression, we have analyzed the evolution of COVID-19 infection in three Italian regions (Puglia, Sardinia, Sicilia) with different beta-thalassemic prevalences, in order to search a link. The results have showed that betathalassemic heterozygote population prevalence is correlated to immunity against COVID-19, by a regression. This paper is only for academic discussion, the hypotheses and conclusions needs to be confirmed by further research .
CASE REPORT | doi:10.20944/preprints202007.0178.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: Aviptadil; Vasoactive Intestinal Peptide; VIP; SARS-CoV-2; COVID-19; Corona Virus; Acute Respiratory Distress Syndrome; ARDS; Acute Lung Injury; ALI; surfactant; Alveolar Type II; ATII
Online: 2 August 2020 (18:16:20 CEST)
RLF-100 (Aviptadil), a synthetic form of Vasoactive Intestinal Peptide (VIP) is shown to block replication of the SARS-CoV-2 virus and has been granted Fast Track Designation by the US FDA for the treatment of Critical COVID-19 with Respiratory Failure. We describe the clinical course of the first patient treated with this investigational medication in an open label manner -- a 54 year old patient suffering antibody-mediated rejection of his double lung transplant who contracted COVID-19 with respiratory failure refractory to all currently available therapies. He received three infusions of RLF-100 under an FDA-approved emergency use IND. Within 24 hours of the third infusion, substantial improvement in oxygen saturation and radiographic improvement in characteristic COVID-19 pneumonitis was noted. He was discharged from intensive care at that point and scheduled for discharge to home at 1 week on room air. Despite an intervening hospitalization for trauma, he remains alive and free of respiratory failure at 28 days post treatment.
BRIEF REPORT | doi:10.20944/preprints202002.0242.v2
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: COVID-19; molecular docking; HIV protease inhibitor; nucleotide analogues
Online: 29 February 2020 (12:43:40 CET)
The outbreak of novel coronavirus (COVID-19) infections in 2019 is in dire need of finding potential therapeutic agents. In this study, we used molecular docking to repurpose HIV protease inhibitors and nucleoside analogues for COVID-19, with evaluations based on docking scores calculated by AutoDock Vina and RosettaCommons. Our results suggest that Indinavir and Remdesivir possess the best docking scores, and comparison of the docking sites of the two drugs reveal a near perfect dock in the overlapping region of the protein pockets. After further investigation of the functional regions inferred from the proteins of SARS coronavirus, we discovered that Indinavir does not dock on any active sites of the protease, which may give rise to concern in regards to the efficacy of Indinavir. On the other hand, the docking site of Remdesivir is not compatible with any known functional regions, including template binding motifs, polymerization motifs and nucleoside triphosphate (NTP) binding motifs. However, when we tested the active form (CHEMBL2016761) of Remdesivir, the docking site revealed a perfect dock in the overlapping region of the NTP binding motif. This result suggests that Remdesivir could be a potential therapeutic agent. Clinical trials still must be done in order to confirm the curative effect of these drugs.
REVIEW | doi:10.20944/preprints202007.0613.v3
Subject: Biology, Other Keywords: infective dose; SARS-CoV-2; COVID-19; respiratory viruses; viral load; viral dynamics
Online: 7 December 2020 (11:36:05 CET)
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is pandemic. Prevention and control strategies require an improved understanding of SARS-CoV-2 dynamics. We did a rapid review of the literature on SARS-CoV-2 viral dynamics with a focus on infective dose. We sought comparisons of SARS-CoV-2 with other respiratory viruses including SARS-CoV-1 and MERS-CoV. We examined laboratory animal, and human studies. The literature on infective dose, transmission, and routes of exposure was limited specially in humans, and varying endpoints were used for measurement of infection. We propose the minimum infective dose of COVID-19 in humans, is higher than 100 particles, possibly slightly lower than the 700 particles estimated for H1N1 influenza. Despite variability in animal studies, there was some evidence that increased dose at exposure correlated with higher viral load clinically, and severer symptoms. Higher viral load measures did not reflect COVID-19 severity. Aerosol transmission seemed to raise the risk of more severe respiratory complications in animals. An accurate quantitative estimate of the infective dose of SARS-CoV-2 in humans is not currently feasible and needs further research. Further work is also required on the relationship between routes of transmission, infective dose, co-infection, and outcomes.
REVIEW | doi:10.20944/preprints202004.0204.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: Covid-19; coronavirus; cardiovascular disease; thrombosis; hypertension; endothelial dysfunction
Online: 13 April 2020 (02:23:33 CEST)
The symptoms most commonly reported by patients affected by coronavirus disease 2019 (COVID-19) include cough, fever, and shortness of breath. However, other major events usually observed in COVID-19 patients (e.g. high blood pressure, thrombosis, pulmonary embolism) seem to suggest that the virus is targeting the endothelium, one of the largest organs in the human body. Herein, we report both clinical and preclinical evidence supporting the hypothesis that the endothelium is a key target organ of COVID-19.
COMMUNICATION | doi:10.20944/preprints202006.0044.v1
Subject: Life Sciences, Microbiology Keywords: Epidemiology; COVID-19; coronavirus; bat; RaTG13; BtCoV/4991; SARS-CoV-2; Pangolin Coronavirus; next generation sequencing
Online: 5 June 2020 (06:17:26 CEST)
A recent manuscript (Zhou, P. et al. “A pneumonia outbreak associated with a new coronavirus of probable bat origin”, Nature 579, 270–273 (2020). https://doi.org/10.1038/s41586-020-2012-7) from Wuhan Institute of Virology claimed the identification of a bat coronavirus, RaTG13, which showed 96.2% genome homology with SARS-CoV-2. In this paper, we raise the puzzling observations surrounding the identification, characterization, unique genome features of this RaTG13 strain, as well as its 100% nucleotide identity in partial RdRp gene with another bat coronavirus strain BtCoV/4991. And the paper presented premature hypothesis of potential bat origin of SARS-CoV-2 while RaTG13 strain was not successfully isolated. We also present the concerns on the methodology, data quality and experiment procedures described in this paper. We call for the authors to provide additional data, to share related samples to be verified and further characterized by other scientists.
ARTICLE | doi:10.20944/preprints202003.0356.v1
Subject: Life Sciences, Genetics Keywords: COVID-19; SARS-CoV-2; host genetics; genetics; polygenic risk score
Online: 24 March 2020 (08:36:20 CET)
The global pandemic of COVID-19 accounts for more than 14,000 deaths worldwide. However, little is known about the host genetics interaction with infection and COVID-19 progression. To better understand the role of host genetics, we review the current literature, aggregate readily available genetic resources, and provide some updated analysis relevant to COVID-19 and associated phenotypes. Using the unrelated individuals in UK Biobank (total n = 337,579 across 5 populations), we aggregate human leukocyte antigen and ABO blood type frequencies. We find significant and consistent risk reduction of blood group O reported in Zhao et al. and encourage broad sharing of ABO blood type frequencies that are readily accessible across COVID-19 with mild, moderate, and severe/critical symptoms for robust inferences at https://tinyurl.com/abo-covid19. In addition, we generate polygenic risk scores (PRSs) weights for 29 blood measurements, including clinically relevant haematological measurements for COVID-19, such as lymphocyte count and percentage. Focusing on the 8 most COVID-19 clinically relevant blood measurements, we performed PRS-PheWAS analysis across 44 disease antigen measurements (n = 6,643 unrelated individuals in White British group), infectious diseases and acute respiratory infections (n = 20,928 cases and 349,000 controls across 3 population groups) and deaths (n = 1,846 cases and 368,082 controls), recorded in hospital inpatient record and death registry data, respectively, in UK Biobank, and find host genetic PRS associations with disease risk. Taken together, we anticipate these resources (https://github.com/rivas-lab/covid19) will aid in improving our understanding of host genetic risk factors playing a role in SARS-CoV-2 infection and COVID-19 disease severity.
ARTICLE | doi:10.20944/preprints202002.0258.v2
Subject: Life Sciences, Genetics Keywords: SARS-CoV-2; cell-entry receptor; ACE2; The Cancer Genome Atlas; susceptibility; demographic factors; polymorphism
Online: 25 February 2020 (06:30:17 CET)
The recurrent coronavirus outbreaks in China (SARS-CoV and its relative, SARS-CoV-2) have raised speculations that perhaps Asians are somehow more susceptible to these coronaviruses. Here, we test this possibility based on an analysis of the lung-specific expression of ACE2, which encodes the known cell-entry receptor of both SARS-CoV and SARS-CoV-2. We show that ACE2 expression is not affected during tumorigenesis, supporting that the abundant transcriptomes in cancer genomic studies can be informatively used to study ACE2 expression among diverse individuals without cancer. We find that ACE2 expression in the lung increases with age, but is not associated with sex. Further, Asians do not differ from other populations for ACE2 expression and do not harbor unique genetic polymorphisms in the ACE2 locus. Thus, beyond illustrating an innovative method for assessing the potential impacts of demographic factors for non-cancer diseases from large-scale cancer sample datasets, our statistically robust findings emphasize that individuals of all races require the same level of personal protection against SARS-CoV-2.
HYPOTHESIS | doi:10.20944/preprints202004.0090.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: COVID-19: hydroxychloroquine aerosol; pharmacotherapy; prevention; SARS-CoV-2
Online: 7 April 2020 (11:11:09 CEST)
Covid-19 is a new coronavirus disease first described in December 2019. This respiratory illness is severe and potentially fatal. Severe cases make up to 15%, lethality ranges between 1.5 and more than 10 %. What is urgently needed is an efficient pharmacological treatment for the treatment of severe cases. During the infection of alveolar epithelial cells of the lung, the ACE2 receptor has a central function. The antimalarial drugs chloroquine phosphate (CQ) and hydroxychloroquine (HCQ) impair in vitro the terminal glycosylation of ACE2 without significant change of cell-surface ACE2 and, therefore, might be potent inhibitors of SARS-CoV-2 infections. Starting inhibition at 0.1 µM, CQ completely prevented in vitro infections at 10 µM, suggesting a prophylactic effect and preventing the virus spread 5 hours after infection. In a first clinical trial, CQ was effective in inhibiting exacerbation of pneumonia, improving lung imaging findings, promotion of virus-negative conversion, and shortening the disease. In addition, HCQ, which is three times more potent than CQ in SARS-CoV-2 infected cells (EC50 0.72 µM), was significantly associated with viral load reduction/disappearance in COVID-19 patients compared to controls. Theoretically, CQ and HCQ could thus be effectively used in the treatment of SARS-CoV pneumonia. From a pharmacological standpoint, however, the major problems of oral treatment with these drugs are possible severe side effects and toxicity. Concretely, this relates to (a) the inconsistent individual bioavailability of these drugs at the alveolar target cells, depending on intestinal resorption, hepatic first-pass metabolism and accumulation in liver, spleen and lung, and (b) the need for a relatively high concentration of 1-5 µM at the alveolar surface. Therefore, we propose in a first dose estimation the use of HCQ as an aerosol in a dosage of 2-4 mg per inhalation in order to reach sufficient therapeutic levels at the alveolar epithelial cells. By using a low-dose non-systemic aerosol, adverse drug reactions will markedly be reduced compared with oral application. This increase in tolerability enables a broader use for prevention and after contact with an infected person, which would be an advantage especially for the high-risk, often multi-morbid and elderly patients. Empirical data on self-medication with a one-week aerosol application by two of the authors is presented. Inhalation was well tolerated without relevant side effects.
REVIEW | doi:10.20944/preprints202006.0159.v1
Online: 14 June 2020 (03:18:35 CEST)
Novel coronavirus disease (COVID-19) has affected nearly 7 million individuals and claimed more than 0.4 million lives to date. There are several reports of gender differences related to infection and death due to COVID-19. This raises important questions such as “Whether there are differences based on gender in risk and severity of infection or mortality rate?” and “What are the biological explanation and mechanisms underlying these differences?” Emerging evidence has proposed sex-based immunological, genetic, and hormonal differences to explain this ambiguity. Besides biological differences, women have also faced social inequities and economic hardships due to this pandemic. Several recent studies have shown that independent of age males are at higher risk for severity and mortality in COVID-19 patients. Although susceptibility to SARS-CoV-2 was found to be similar across both genders in several disease cohorts, a disproportionate death ratio in men can be partly explained by the higher burden of pre-existing diseases and occupational exposures among men. From an immunological point of view, females can engage a more active immune response, which may protect them and counter infectious diseases as compared to men. This attribute of better immune responses towards pathogens is thought to be due to high estrogen levels in females. Here we review the current knowledge about sex differences in susceptibility, the severity of infection and mortality, host immune responses, and the role of sex hormones in COVID-19 disease.
ARTICLE | doi:10.20944/preprints202003.0081.v1
Subject: Life Sciences, Biophysics Keywords: COVID-19; electrostatic feature; salt bridging network; structural update
Online: 5 March 2020 (03:37:44 CET)
Since the Coronavirus disease (COVID-19) outbreak at the end of 2019, the past two month has seen an acceleration both in and outside China in the R&D of the diagnostics, vaccines and therapeutics for this novel coronavirus. As one of the molecular forces that determine protein structure, electrostatic effects dominate many aspects of protein behaviour and biological function. Thus, incorporating currently available experimental structures related to COVID-19, this article reports a simple python-based analysis tool and a LaTeX-based editing tool to extract and summarize the electrostatic features from experimentally determined structures, to strengthen our understanding of COVID-19's structure and function and to facilitate machine-learning and structure-based computational design of its neutralizing antibodies and/or small molecule(s) as potential therapeutic candidates. Finally, this article puts forward a brief update of the structurally observed electrostatic features of the COVID-19 coronavirus.
REVIEW | doi:10.20944/preprints202003.0197.v3
Subject: Biology, Other Keywords: Built Environment (BE); building operations; novel coronavirus; COVID-19; SARS-CoV-2
Online: 2 April 2020 (05:19:41 CEST)
With the rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that results in coronavirus disease 2019 (COVID-19), corporate entities, federal, state, county and city governments, universities, school districts, places of worship, prisons, health care facilities, assisted living organizations, daycares, homeowners, and other building owners and occupants have an opportunity to reduce the potential for transmission through built environment (BE) mediated pathways. Over the last decade, substantial research into the presence, abundance, diversity, function, and transmission of microbes in the BE has taken place and revealed common pathogen exchange pathways and mechanisms. In this paper, we synthesize this microbiology of the BE research and the known information about SARS-CoV-2 to provide actionable and achievable guidance to BE decision makers, building operators, and all indoor occupants attempting to minimize infectious disease transmission through environmentally mediated pathways. We believe this information is useful to corporate and public administrators and individuals responsible for building operations and environmental services in their decision-making process about the degree and duration of social-distancing measures during viral epidemics and pandemics.
Subject: Biology, Other Keywords: SARS-CoV-2; RATG13; BtCoV/4991; SARS-like (SL-) corona virus; pneumonia
Online: 24 May 2020 (20:02:22 CEST)
Genomic analysis indicates that SARS-CoV-2 is most related to RaTG13, a beta corona virus derived from bats by 96% 1. At present, RaTG13 is only available on the public database in the form of a genome sequence. The genome of RaTG13 (MN996532.1) was sequenced from the RNA of a bat faecal swab collected in 2013 from Yunnan, China, however the exact location is not mentioned. Since RaTG13 is one of the main supports for SARS-CoV-2 to have a natural origin, it is of utmost importance to understand the sample location. RNA dependent RNA polymerase (RdRp) sequence of RaTG13 shows that it is 100% similar to that of bat corona virus BtCoV/4991 and 98.7-98.9% similar to SARS-CoV-2 RdRp 2. BtCoV/4991 was described to be a SARS-like (SL-) corona virus from bat faeces sampled in an abandoned mine from Mojiang 2. Both the publications 1,2 are authored by Dr. Zheng-li Shi (Z-L Shi), who is described as the bat woman of China 3. However, BtCoV/4991 has not been mentioned by Zhou et al 2020 1 where novel corona virus was first described. Based on the RdRp sequence similarities, similarities in sample collection dates, sample locations, and the fact that RaTG13 is mentioned synonymous to BtCoV/4991 on the Chinese bat database, it is predicted that RaTG13 and BtCoV/4991 originate from the same sample. The sample, bat faecal swab was collected in 2013 from an abandoned mineshaft in Mojiang by Dr. Shi and her work group. In 2012, in a Mojiang mineshaft, six mine workers suffered from atypical pneumonia and three of them died. These workers were engaged in the work of clearing debris from a mineshaft which had a lot of bats and bat faeces 3,4. A detailed health investigation indicated that the miners suffered from atypical pneumonia mostly of the viral origin 4. Therefore, in the light of the present Covid-19 caused by SARS-CoV-2, the fact that its phylogenetic neighbour RaTG13 originated from bat faeces collected from a mineshaft, which was also the origin of pneumonia-like disease in miners in 2012, should be noted.
ARTICLE | doi:10.20944/preprints202006.0013.v1
Subject: Social Sciences, Education Studies Keywords: online education; corona crisis; challenges; possibilities
Online: 3 June 2020 (08:25:46 CEST)
Online class now is the demand of the day as little scopes are to find out alternatives to online class in these unprecedented days caused by corona pandemic across the globe. The study was qualitative in approach and data were collected from secondary sources i.e. different newspapers and journals in the recent times along with a mini interview with students of private universities studying in different subjects over mobile phone by the researcher. Findings of the study show that though online education has a number of challenges faced by two main stakeholders; students and teachers, handling all these challenges carefully can have the chance to create a positive atmosphere in the field of education as an alternative teaching learning resulting in positive outcomes in all regards.
REVIEW | doi:10.20944/preprints202003.0275.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Antimalarial; Chemoprophylaxis; Chloroquine; Coronavirus; COVID-19; Global Health; Hydroxychloroquine; Public Health; SARS-CoV-2; Virus
Online: 17 March 2020 (09:17:53 CET)
There is a long trail of research studies testing the in vitro and in vivo efficacy of chloroquine and its derivatives in treating and preventing infection by various coronavirus species. More recent findings have highlighted the possibility of treating patients infected with the 2019 novel coronavirus, SARS-CoV-2. This review describes the mechanism of coronavirus infection, the mechanism of action of chloroquine, and summarizes the available literature highlighting the efficacy of chloroquine as an anti-coronavirus agent. These findings should encourage the wider scientific community to conduct thorough research on the possible efficacy of chloroquine and its derivatives in treating and preventing SARS-CoV-2 infection.
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: Novel coronavirus pneumonia; COVID-19; SARS-CoV-2; Pathology; Critical patient
Online: 9 March 2020 (10:31:10 CET)
Background Critical patients with novel coronavirus pneumonia ( COVID-19) have worse outcome and high mortality. However, the histopathology of critical patient with COVID-19 remains undisclosed. Methods We performed the whole lung biopsy, and described the pathological changes of critical COVID-19 patient done with transplant by HE staining, immunohistochemistry and special staining observed under the microscopy. Findings The whole lungs displayed diffuse congestive appearance and partly haemorrhagic necrosis on gross examination. The haemorrhagic necrosis was prominently present in outer edge of the right lower lung. The cut surfaces of the lung displayed severe congestive and haemorrhagic changes. The main pathological changes showed massive pulmonary interstitial fibrosis, and partly hyaline degeneration, variable degrees of hemorrhagic pulmonary infarction. Small vessels hyperplasia, vessel wall thickening, lumen stenosis, occlusion and microthrombosis formation. Focal monocytes, lymphocytes and plasma cells infiltrating into pulmonary interstitium. Bronchiolitis and alveolitis with proliferation, atrophy, desquamation and squamous metaplasia of epithelial cells. Atrophy, vacuolar degeneration, proliferation, desquamation and squamous metaplasia in alveolar epithelial cells. Alveolar cavity congestion was prominent, and contained mucus, edema fluid, desquamated epithelial cells, and inflammatory cells. We also found several multinucleate giant cells and intracytoplasmic viral inclusion bodies. Special stains including Masson stain, sirius red staining, reticular fibers staining indicated massive pulmonary interstitial fibrosis. Immunohistochemistry showed positive for immunity cells including CD3, CD4, CD8, CD20, CD79a, CD5, CD38 and CD68. Interpretation We demonstrate the pathological findings of critical patient with COVID-19, which might provide a deep insight of the pathogenesis and severity of this disease.
CONCEPT PAPER | doi:10.20944/preprints202004.0432.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: SARS CoV-2; COVID-19; Nitazoxanide; Azithromycin; Interferons
Online: 24 April 2020 (09:24:23 CEST)
Azithromycin has been shown to have a clinical efficacy against severe acute respiratory syndrome coronavirus 2 (SARS CoV-2); ivermectin has also demonstrated a remarkable experimental efficacy with a potential to be used for Coronavirus disease 2019 (COVID-19). Further, BCG vaccination is being considered for clinical trials aiming to test its potential for lowering COVID-19 morbidity and mortality. This article illustrates some structural and functional relationships that may gather these drugs and the author, basing on a combined pathophysiological and pharmacological approach, recommends the FDA-approved antidiarrhea drug; nitazoxanide, which has been previously suggested but unfortunately ignored, to be tested in combination with azithromycin for their potential activity against SARS CoV-2 soonest. The author recommends testing their combined administration as early during the clinical course of COVID-19 as possible. Further, basing on the same represented concept, the author recommends more trials for interferons to be tested against SARS CoV-2 especially in severe and critical cases.
ARTICLE | doi:10.20944/preprints202003.0311.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: SARS-CoV-2; COVID-19; pathology; post-mortem biopsy
Online: 20 March 2020 (09:24:10 CET)
Data on pathologic changes of the 2019 novel coronavirus disease (COVID-19) are scarce. To gain knowledge about the pathology that may contribute to disease progression and fatality, we performed post-mortem needle core biopsies of lung, liver, and heart in four patients who died of COVID-19 pneumonia. The patients’ ages ranged from 59 to 81, including 3 males and 1 female. Each patient had at least one underlying disease, including immunocompromised status (chronic lymphocytic leukemia and renal transplantation) or other conditions (cirrhosis, hypertension, and diabetes). Time from disease onset to death ranged from 15 to 52 days. All patients had elevated white blood cell counts, with significant rise toward the end, and all had lymphocytopenia except for the patient with leukemia. Histologically, the main findings are in the lungs, including injury to the alveolar epithelial cells, hyaline membrane formation, and hyperplasia of type II pneumocytes, all components of diffuse alveolar damage. Consolidation by fibroblastic proliferation with extracellular matrix and fibrin forming clusters in airspaces is evident. In one patient, the consolidation consists of abundant intra-alveolar neutrophilic infiltration, consistent with superimposed bacterial bronchopneumonia. The liver exhibits mild lobular infiltration by small lymphocytes, and centrilobular sinusoidal dilation. Patchy necrosis is also seen. The heart shows only focal mild fibrosis and mild myocardial hypertrophy, changes likely related to the underlying conditions. In conclusion, the post-mortem examinations show advanced diffuse alveolar damage, as well as superimposed bacterial pneumonia in some patients. Changes in the liver and heart are likely secondary or related to the underlying diseases.
Subject: Medicine & Pharmacology, Allergology Keywords: Coronavirus; SARS-CoV-2; COVID-19; Thalidomide; pneumonia
Online: 26 February 2020 (12:31:47 CET)
A novel coronavirus strain (severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first appeared in December 2019 and can cause acute respiratory distress syndrome and death. However, there are only limited therapy choices and no vaccine for SARS-CoV-2 is currently available. Here we report about a case of a SARS-CoV-2 caused pneumonia successfully treated with thalidomide. Thalidomide is an immunomodulatory and anti-inflammatory agent and was combined with a low-dose glucocorticoid. We suggest, that the effects of thalidomide might be related to regulating immunity, inhibiting the inflammatory cytokine surge, alleviating anxiety to reduce oxygen consumption, relieving vomit and lung exudation.
REVIEW | doi:10.20944/preprints202003.0346.v1
Subject: Medicine & Pharmacology, Other Keywords: COVID-19; nCoV 19; oxidative stress; PARP; PARG; TRPM2
Online: 23 March 2020 (07:40:50 CET)
The emerging new Coronaviridae member, nCoV 19, outbreak announced a pandemic by WHO with an increased morbidity and mortality rate worldwide. nCoV 19 known as the third highly pathogen coronavirus in the human population after the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle East respiratory syndrome coronavirus (MERS-CoV), the nCoV 19. The renin-angiotensin (RAS) signaling pathway, oxidative stress and cell death, cytokines storm and endothelial dysfunction are four major pathways involved in the pathogenesis of nCoV 19. Acute respiratory distress syndrome (ARDS) generally develops with a massive oxidative/nitrosative stress following virus entry and RAS activation. The DNA damage subsequent to oxidative burst activates poly-ADP ribose polymerase-1 (PARP-1), viral macrodomain (NSP3) poly (ADP-ribose) glycohydrolase (PARG) and transient receptor potential channel, melastatin 2 (TRPM2) in a sequential manner ultimately leading to apoptosis and necrosis due to NAD and ATP depletion. Regarding the molecular mechanisms involved in nCoV 19 pathogenesis, angiotensin II receptor blockers and/or PARP, PARG and TRPM2 blockers could be engaged as therapeutic candidates for inhibition of RAS and quenching oxidative stress, respectively. In this review, the molecular aspects of nCoV 19 pathogenesis would be studied precisely and possible therapeutic targets would be proposed. It is recommended to evaluate the proposed drugs and supplements via registered clinical trials along with conventional guideline-based multi-drug regimen.
ARTICLE | doi:10.20944/preprints202003.0302.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: COVID-2019; SARS-CoV-2; 2019-nCoV; repositioning; UPR/Autophagy; real-world evidence; pathways
Online: 20 March 2020 (03:55:55 CET)
More than 179,000 individuals have fallen ill of the Coronavirus disease (COVID-19) caused by the SARS-CoV-2 virus, which first emerged in China less than four months ago in December 2019. As of today, there exist no approved treatments against COVID-19. Vaccines are being developed, but they will take time, at least one year, to reach the population. Drug repositioning represents a fast track because already approved medicines have been broadly tested through multiple trials. We developed a repositioning strategy that mostly leads to candidates that are commonly used. The advantages are that they will facilitate proof of concept in humans through a “real-world evidence” approach and should be rapidly available to the population. We focus on the established research results that the unfolded protein response (UPR) and autophagy pathways of the host cells are essential to the life cycle of previously known coronaviruses. We performed the relevant bioinformatics analysis to understand and confirm if SARS-CoV-2 may interact with these druggable pathways. Based on these considerations, we prioritized two additional druggable pathways, which are important to the viral life cycle and tightly connected to UPR/autophagy signaling: the mitochondrial permeability transition pores (MPTP) and NLRP-3 inflammasome pathways. These four important pathways are perturbed in most major common diseases and have therefore been targeted by numerous broadly prescribed drugs. We have identified 97 approved drugs that are known to modulate these four identified pathways, and which represent, therefore, interesting repositioning candidates. Although it is indisputable that these drugs should never be used for immediate self-medication against COVID-19, we notice that some of them could also be prescribed to individuals who have COVID-19 comorbidities (e.g., hypertension). It is debated if these comorbidities are linked to the pathology itself (e.g., hypertension) or the drugs used to treat the pathology (e.g., sartans). Therefore, relevant preclinical tests and massive electronic health records (i.e., real-world evidence) must be used to pre-screen them and check the COVID-19 prognosis of individuals taking these drugs.
ARTICLE | doi:10.20944/preprints202004.0374.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; coronavirus; infectious disease; infection management; PCR test; mortality; kinetic analysis
Online: 3 June 2020 (05:10:05 CEST)
Global differences in changes in the numbers of population-adjusted daily test-positive cases (NPDP) and deaths (NPDD) by COVID-19 were analyzed for 49 countries, including developed and developing countries. The changes as a proportion of national population were compared, adjusting by the beginning of test-positive cases increase (BPI) or deaths increase (BDI). Remarkable regional differences of more than 100 fold in NPDP and NPDD were observed. The trajectories of NPDD after BDI increased exponentially within 20 days in most countries. Machine learning analysis suggested that NPDD on 30 days after BDI was the highest in developed Western countries (1180 persons per hundred million), followed by countries in the Middle East (128), Latin America (97), and Asia (7). Furthermore, in Western countries with positive rates of the PCR test of less than 7.0%, the increase in NPDP was slowing-down two weeks after BPI, and subsequent NPDD was only 15% compared with those with higher positive rates, which suggested that the situation of testing might have affected the velocity of COVID-19 spread. The causes behind remarkable differences between regions possibly include genetic factors of inhabitants because distributions of the race and of the observed infection increasing rates were in good agreement globally.
ARTICLE | doi:10.20944/preprints202004.0345.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; venous thrombosis; pulmonary embolism; venous thromboembolism; anticoagulants; mortality
Online: 19 April 2020 (13:08:16 CEST)
Coronavirus disease 2019 (COVID-19) can lead to systemic coagulation activation and thrombotic complications. We investigated the incidence of objectively confirmed venous thromboembolism (VTE) in 198 hospitalized patients with COVID-19 in a single-center cohort study. Seventy-four patients (37%) were admitted to the intensive care unit (ICU). At time of data collection, 58 (29%) were still hospitalized and 14% had died. During a median follow-up of 5 days (IQR, 3-9), 33 patients (17%) were diagnosed with VTE of whom 22 (11%) had symptomatic VTE, despite routine thrombosis prophylaxis. The cumulative incidences of VTE at 7 and 14 days were 15% (95% CI, 9.3-22) and 34% (95% CI, 23-46), respectively. For symptomatic VTE, these were 11% (95% CI, 5.8-17) and 23% (95% CI, 14-33). VTE appeared to be associated with death (adjusted HR, 2.9; 95% CI, 1.02-8.0). The cumulative incidence of VTE was higher in the ICU (25% at 7 days 95% CI, 15-36, and 48% at 14 days, 95% CI, 33-61) than on the wards (any VTE and symptomatic VTE 6.5 % at 7 days (95% CI, 1.5-17) and 10% at 14 days (95% CI, 2.9-24)).The observed risk for VTE in COVID-19 is high, particularly in ICU patients, which should lead to a high level of clinical suspicion and low threshold for diagnostic imaging for DVT or PE. Future research should focus on optimal diagnostic and prophylactic strategies to prevent VTE and potentially improve survival.
ARTICLE | doi:10.20944/preprints202003.0347.v1
Online: 23 March 2020 (07:46:54 CET)
SARS-CoV-2 is the causative agent for the ongoing COVID19 pandemic, and this virus belongs to the Coronaviridae family. Like other members of this family, the virus possesses a positive-sense single-stranded RNA genome. The genome encodes for the nsp12 protein, which houses the RNA-dependent-RNA polymerase (RdRP) activity responsible for the replication of the viral genome. A homology model of nsp12 was prepared using the structure of the SARS nsp12 (6NUR) as a model. The model was used to carry out in silico screening to identify molecules among natural products, or FDA approved drugs that can potentially inhibit the activity of nsp12. This exercise showed that vitamin B12 (methylcobalamin) may bind to the active site of the nsp12 protein. A model of the nsp12 in complex with substrate RNA and incoming NTP showed that Vitamin B12 binding site overlaps with that of the incoming nucleotide. A comparison of the calculated energies of binding for RNA plus NTP and methylcobalamin suggested that the vitamin may bind to the active site of nsp12 with significant affinity. It is, therefore, possible that methylcobalamin binding may prevent association with RNA and NTP and thus inhibit the RdRP activity of nsp12. Overall, our computational studies suggest that methylcobalamin form of vitamin B12 may serve as an effective inhibitor of the nsp12 protein.
ARTICLE | doi:10.20944/preprints202003.0161.v1
Subject: Life Sciences, Microbiology Keywords: coronaviruses receptors; angiotensin-converting enzyme 2 (ACE2); COVID-19; SARS-Cov-2; the Red Queen hypothesis; segmented filamentous bacteria
Online: 10 March 2020 (08:45:34 CET)
Understanding how the coronaviruses invade our body is an essential point, and the expression profile of coronaviruses receptor may help us to find where the coronavirus infects our body. We found that the coronavirus receptors, including angiotensin-converting enzyme 2 (ACE2) for SARS-CoV and SARS-Cov-2, are digestion-related enzymes in human enterocytes. Coronaviruses are continually altering the binding receptor and binding modes during their evolution, but the potential target cell in the small intestine is constant when in the lung is inconstant. Enterocytes may act as a conserved cell reservoir for coronaviruses, which may be partially explained by the Red Queen hypothesis. We also found that coronaviruses receptors could be elevated in the presence of both invasive bacteria and their counterpart, probiotics. We demonstrated here that enterocytes act as a conserved cell reservoir for coronaviruses during their evolutions, which should not be ignored in the investigation of coronavirus diagnosis and treatment strategies.
BRIEF REPORT | doi:10.20944/preprints202002.0424.v1
Subject: Keywords: SARS-CoV-2; Korean COVID-19; Wuhan Corona virus; real time PCR Ct Value; Sensitivity; False Negative
Online: 28 February 2020 (12:03:13 CET)
Since mid-December of 2019, coronavirus disease 2019 (COVID-19) has been spreading from Wuhan, China. As of February 21, total 75,773 confirmed cases worldwide have spread to more than two dozen countries. Transmission of COVID-19 can occur early in the course of infection since SARS-CoV-2 viral loads in asymptomatic patients are similar to that in the symptomatic patients. Therefore, more sensitive diagnostic methods are needed to detect early phase of the infection to prevent secondary or tertiary spreads. Here, we compare the RT-PCR confirmatory test results using two different SARS-CoV-2 viral RNAs from two Korean COVID-19 confirmed cases.RT-PCR method targeting the RdRP gene, which was recommended by WHO guideline, was less sensitive than targeting N genes (as per CDC guideline). Because many countries follow the WHO guideline, our findings may contribute to the early diagnosis of COVID-19.
REVIEW | doi:10.20944/preprints202002.0283.v1
Online: 19 February 2020 (11:58:13 CET)
The latest emergence of a novel coronavirus (COVID-19) had caused an outbreak of respiratory virus infections in Wuhan, China, and other countries so that the world health organization (WHO) declared the COVID-19 epidemic as a Public Health Emergency of International Concern (PHEIC) on January 31, 2020. At present, it is the fact that we have identified the bats as the host, the route of respiratory droplets, contact, and aerosol can accelerate the transmission from person to person. However, it is not well known about the intermediator and other approaches. Identifying and characterizing the origin and host(s) of COVID-19 can help us to evaluate the potential risk of COVID-19 for transmission among humans or cross-species.
ARTICLE | doi:10.20944/preprints202003.0206.v2
Subject: Medicine & Pharmacology, Other Keywords: 2019 novel coronavirus infection; corons; SARS-CoV; interferon; systems biology
Online: 23 March 2020 (10:27:57 CET)
As the outbreak of COVID-19 has accelerated, an urgent need for finding strategies to combat the virus is growing. Thus, gaining more knowledge on the pathogenicity mechanisms of SARS-CoV-2, the causing agent of COVID-19, and its interaction with the immune system is of utmost importance. Although this novel virus is not well known yet, its structural and genetic similarity with SARS-CoV as well as the comparable pattern of age-mortality relations suggest that the previous findings on SARS can be applicable for COVID-19. Therefore, a systems biology study was conducted to investigate the most important signaling pathways activated by the virus. The results were then validated through a literature review on COVID-19 and the other closely related viruses, SARS and MERS. Interferons have shown to play a crucial role in the defense against coronavirus diseases. CoV can impede the interferon induction in humans. Moreover, STAT1, a key protein in the interferon-mediated immune response, is antagonized by the virus. This could explain the increased response threshold of immune cells to IFNs during CoV infections. A vivid correlation between the innate immune response threshold and the fatality rates in COVID-19 can be found. Differences in the dynamics of the interferon-related innate immune responses in children, adults, and elderly may explain the reported fatality rates. The increased mortality rates in the elderly can be explained by the higher threshold of interferon-mediated immune responses. Earlier induction of interferons in children and their less developed immune system could contribute to their near to zero fatality rate. Administration of interferon-inducing agents, such as poly (ICLC), could reduce the mortality of SARS at the very early stages of the disease. Interferon-γ combination with an interferon-I might induce synergistic effects and maximize the benefits. However, in-depth research is needed to validate it and determine the optimum dosage and timing to prevent unwanted results. Such interventions can act as a double-edged sword and aid the imbalance of the immune reactions, which may occur at the later stages of the disease. With the advancement of the disease and the virus overload, the responses would shift toward immnopathogenic over-reactions and probably cytokine storm. Moderating the activity of the immune system and supportive care in such conditions might be the optimum approach.
REVIEW | doi:10.20944/preprints202003.0001.v2
Subject: Medicine & Pharmacology, Other Keywords: emerging coronavirus; 2019-nCoV; SARS-CoV-2; COVID-19; diagnosis; vaccines; therapy; one health
Online: 13 April 2020 (02:29:00 CEST)
In the past decades, several new diseases have emerged in new geographical areas, with pathogens including Ebola, Zika, Nipah, and coronaviruses (CoVs). Recently, a new type of viral infection has emerged in Wuhan City, China, and initial genomic sequencing data of this virus does not match with previously sequenced CoVs, suggesting a novel CoV strain (2019-nCoV), which has now been termed as severe acute respiratory syndrome CoV-2 (SARS-CoV-2). Although Coronavirus disease 2019 (COVID-19) is suspected to originate from an animal host (zoonotic origin) followed by human-to-human transmission, the possibility of other routes such as food-borne transmission should not be ruled out. Compared to diseases caused by previously known human CoVs, COVID-19 shows less severe pathogenesis but higher transmission competence, as is evident from the continuously increasing number of confirmed cases globally. Compared to other emerging viruses such as Ebola virus, avian H7N9, SARS-CoV, or MERS-CoV, SARS-CoV-2 has shown relatively low pathogenicity and moderate transmissibility. Codon usage studies suggest that this novel virus may have been transferred from an animal source such as bats. Early diagnosis by real-time PCR and next-generation sequencing has facilitated the identification of the pathogen at an early stage. Since, no antiviral drug or vaccine exists to treat or prevent SARS-CoV-2, potential therapeutic strategies that are currently being evaluated predominantly stem from previous experience with treating SARS-CoV, MERS-CoV, and other emerging viral diseases. In this review, we address epidemiological, diagnostic, clinical, and therapeutic aspects, including perspectives of vaccines and preventive measures that have already been globally recommended.
ARTICLE | doi:10.20944/preprints202003.0267.v1
Subject: Chemistry, Physical Chemistry Keywords: COVID-19; SARS-CoV-2; RNA-dependent RNA polymerase (RdRp); remdesivir; homology model; molecular dynamics; free energy perturbation
Online: 17 March 2020 (04:07:15 CET)
Starting from December 2019, coronavirus disease 2019 (COVID-19) has emerged as a once-in-a-century pandemic with deadly consequences, which urgently calls for new treatments, cures and supporting apparatuses. Remdesivir was reported by World Health Organization (WHO) as the most promising drug currently available for the treatment of COVID-19. Here, we use molecular dynamics simulations and free energy perturbation methods to study the inhibition mechanism of remdesivir to its target SARS-CoV-2 virus RNA-dependent RNA polymerase (RdRp). In the absence of a crystal structure of the SARS-CoV-2 RdRp, we first construct the homology model of this polymerase based on a previously available structure of SARS-CoV NSP12 RdRp (with a sequence identify of 95.8%). We then build the putative binding mode by aligning the remdesivir + RdRp complex to the ATP bound poliovirus RdRp. The putative binding structure is further optimized with molecular dynamics simulations and demonstrated to be stable, indicating a reasonable binding mode for remdesivir. The relative binding free energy of remdesivir is calculated to be -8.28 ± 0.65 kcal/mol, much stronger than the natural substrate ATP (-4.14 ± 0.89 kcal/mol) which is needed for the polymerization. The ~800-fold improvement in the Kd from remdesivir over ATP indicates an effective replacement of APT in blocking of the RdRp binding pocket. Key residues D618, S549 and R555 are found to be the contributors to the binding affinity of remdesivir. These findings demonstrate that remdesivir can potentially act as a SARS-CoV-2 RNA-chain terminator, effectively stopping its RNA reproduction, with key residues also identified for future lead optimization and/or drug resistance studies.
ARTICLE | doi:10.20944/preprints202104.0702.v1
Subject: Social Sciences, Accounting Keywords: COVID-19; vaccine acceptance; vaccine willingness; vaccine hesitancy; quantitative; online survey; Philippines
Online: 27 April 2021 (10:12:47 CEST)
With COVID-19 vaccines slowly being rolled out in many countries, it is important to understand the public’s acceptance of being vaccinated. This study aims to study the willingness and motivations among residents of the cities of Caloocan, Malabon, and Navotas, Philippines to be vaccinated against COVID-19. Based on an online survey of 137 respondents, who willingly participated in the study, 71% will take a COVID-19 vaccine if it becomes available, with similar rates among respondents from Caloocan (82%), Malabon (83 %), and Navotas (81%). If a vaccine is proven safe and effective, more respondents (82%) will take a COVID-19 vaccine. Furthermore, safety against COVID-19 as well as the safety and effectiveness of vaccines are the primary factors why respondents are willing or unwilling to get a vaccine. The results highlight the need for effective messaging that promotes COVID-19 vaccination, with emphasis on the safety and effectiveness of the vaccine, and its benefits to the public, especially that the vaccines that will be delivered in the country in the next few months are not the most preferred brands by the respondents.
REVIEW | doi:10.20944/preprints202005.0265.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: vitamin D; cathelicidin; antimicrobial peptides; bacteria; mycobacteria; virus; coronavirus; sunshine; UVB phototherapy; tuberculosis; COVID-19; photosynthesis
Online: 16 May 2020 (16:02:26 CEST)
Abstract: A primary action of vitamin D is regulation of gene transcription. Many cell types possess genes that make antimicrobial peptides (AMPS) (endogenous antibiotics), recently discovered to be regulated by vitamin D. Two examples are cathelicidin and beta defensins, both bioactive against many different bacteria, fungi, mycobacteria, parasites and viruses. The signal transduction pathway is triggered by sensing microorganisms via cell surface receptors, causing intracellular production of calcitriol (1,25(OH)2D) and vitamin D receptors, leading to upregulation of AMP production. Serum 25(OH)D concentrations required to sustain adequate AMP production to eradicate infections are unknown. Vitamin D3 is photosynthesized in skin in amounts ranging from 10,000 (250 mcg) to 25,000 (625 mcg) International Units (IU) from 7-dehydrocholesterol after whole-body exposure to one minimal erythemal dose (MED) of ultraviolet B (UVB) radiation, and is impacted by many factors including geographic localities, seasonal changes and skin pigmentation. We and others have reported extended daily oral dosing with these amounts of vitamin D3 safe. We routinely observe serum 25(OH)D concentrations below 20ng/ml on new admissions, which have been reported insufficient to sustain AMP production. In contrast serum 25(OH)D concentrations above 100ng/ml have been reported after serial UVB treatments for psoriasis. Little vitamin D naturally occurs in food, and insufficient sun exposure may be causing worldwide deficiency. We review evidence suggesting that higher daily intakes of vitamin D3 than the currently recommended 600 (15 mcg) IU/day may be necessary to sustain AMP production in the face of an overwhelming infection, particularly in non-Hispanic blacks, a high risk population suffering the worst outcomes from COVID-19. We propose that increased vitamin D supplementation could provide a safe and cost-effective way to protect all populations from infections, in particular those from pandemic COVID-19.
ARTICLE | doi:10.20944/preprints202002.0061.v1
Online: 5 February 2020 (10:59:09 CET)
A novel coronavirus called 2019-nCoV was recently found in Wuhan, Hubei Province of China, and now is spreading across China and other parts of the world. 2019-nCoV spreads more rapidly than SARS-CoV. Unfortunately, there is no drug to combat the virus. It is of high significance to develop a drug that can combat the virus effectively before the situation gets worse. It usually takes a much longer time to develop a drug using traditional methods. For 2019-nCoV, it is now better to rely on some alternative methods to develop drugs that can combat such a disease effectively since 2019-nCoV is highly homologous to SARS-CoV. In this paper, we first collected virus RNA sequences from the GISAID database, translated the RNA sequences into protein sequences, and built a protein 3D model using homology modeling. Coronavirus main protease is considered to be a major therapeutic target, thus this paper focused on drug screening based on the modeled 2019-nCov_main_protease structure. The deep learning based method DFCNN, developed by our group, can identify/rank the protein-ligand interactions with relatively high accuracy. DFCNN is capable of performing virtual screening quickly since no docking or molecular dynamic simulation is needed. DFCNN identifies potential drugs for 2019-nCoV protease by performing drug screening against 4 chemical compound databases. Also, we performed drug screening for all tripeptides against the binding site of 2019-nCov_main_protease since peptides often show better stability, more bio-availability and negligible immune responses. In the end, we provided the list of possible chemical ligands and peptide drugs for experimental validation.
ARTICLE | doi:10.20944/preprints202012.0199.v2
Online: 14 December 2020 (11:54:04 CET)
School closures (SC) were adopted globally as a COVID-19 disease pandemic containment strategy. This extreme measure provoked a disruption of the educational system involving hundreds of million children worldwide. The return of children to school has been variable and is still an unresolved and contentious issue. Importantly the process has not been directly correlated to the severity of the pandemic s impact and has fueled the widening of disparities, disproportionately affecting the most vulnerable populations. Available evidence shows SC added little benefit to COVID-19 control whereas the harms related to SC severely affected children and adolescents. This unresolved issue has put children and young people at high risk of social, economic and health-related harm for years to come, triggering severe consequences during their lifespan. In this article we describe the process of SC and the reopening timetable across the globe. We highlight the data regarding the international state of educational systems around the world, putting emphasis on the rights of children to come back to school.
ARTICLE | doi:10.20944/preprints202005.0148.v1
Subject: Social Sciences, Economics Keywords: Covid-19; Indian economy; supply chain; manufacturing industries; barriers
Online: 9 May 2020 (10:01:56 CEST)
At present time world is facing from the coronavirus disease known as Covid-19. The first case of the coronavirus was reported in the December, 2019 in the Wuhan city of China which is known as the major transportation hub of China. After the spread of Covid-19 many countries have shut down their sea ports and airports. They have banned the import and export activities. Also, China is the major distributor of the raw materials which affect the manufacturing activities across the globe due to lockdowns. India is the developing country due to the Covid-19 spread the cases reported in the India government has lockdown the country for 41 days which affected the manufacturing activities and majorly it affects the supply chains and economy of the country. In the present paper we have discussed the effect of Covid-19 on Indian economy and on supply chains in India. There are total of 18 critical barriers are found out which affected the supply chains in the India. It is expected that this study will helpful the researchers to develop the conceptual models to overcome from this issue.
HYPOTHESIS | doi:10.20944/preprints202003.0138.v1
Subject: Life Sciences, Virology Keywords: 2019-nCoV; SARS-CoV-2; COVID-19; ADE; antibody depedendent enhancement
Online: 8 March 2020 (15:35:27 CET)
Background: In 80% of patients, COVID-19 presents as mild disease1,2. 20% of cases develop severe (13%) or critical (6%) illness. More severe forms of COVID-19 present as clinical severe acute respiratory syndrome, but include a T-predominant lymphopenia3, high circulating levels of proinflammatory cytokines and chemokines, accumulation of neutrophils and macrophages in lungs, and immune dysregulation including immunosuppression4. Methods: All major SARS-CoV-2 proteins were characterized using an amino acid residue variation analysis method. Results predict that most SARS-CoV-2 proteins are evolutionary constrained, with the exception of the spike (S) protein extended outer surface. Results were interpreted based on known SARS-like coronavirus virology and pathophysiology, with a focus on medical countermeasure development implications. Findings: Non-neutralizing antibodies to variable S domains may enable an alternative infection pathway via Fc receptor-mediated uptake. This may be a gating event for the immune response dysregulation observed in more severe COVID-19 disease. Prior studies involving vaccine candidates for FCoV5,6 SARS-CoV-17-10 and Middle East Respiratory Syndrome coronavirus (MERS-CoV) 11 demonstrate vaccination-induced antibody-dependent enhancement of disease (ADE), including infection of phagocytic antigen presenting cells (APC). T effector cells are believed to play an important role in controlling coronavirus infection; pan-T depletion is present in severe COVID-19 disease3 and may be accelerated by APC infection. Sequence and structural conservation of S motifs suggests that SARS and MERS vaccine ADE risks may foreshadow SARS-CoV-2 S-based vaccine risks. Autophagy inhibitors may reduce APC infection and T-cell depletion12 13. Amino acid residue variation analysis identifies multiple constrained domains suitable as T cell vaccine targets. Evolutionary constraints on proven antiviral drug targets present in SARS-CoV-1 and SARS-CoV-2 may reduce risk of developing antiviral drug escape mutants. Interpretation: Safety testing of COVID-19 S protein-based B cell vaccines in animal models is strongly encouraged prior to clinical trials to reduce risk of ADE upon virus exposure.
BRIEF REPORT | doi:10.20944/preprints202008.0595.v1
Subject: Life Sciences, Molecular Biology Keywords: COVID-19; de novo assembly; metagenomics; data quality
Online: 27 August 2020 (07:56:01 CEST)
An intense scientific debate is ongoing as to the origin of SARS-CoV-2. An oft-cited piece of information in this debate is the genome sequence of a bat coronavirus strain referred to as RaTG13 1 mentioned in a recent Nature paper 2 showing 96.2% genome homology with SARS-CoV-2. This is discussed as a fossil record of a strain whose current existence is unknown. The said strain is conjectured by many to have been part of the ancestral pool from which SARS-CoV-2 may have evolved 7, 8, 9. Multiple groups have been discussing the features of the genome sequence of the said strain. In this paper, we report that the currently specified level of details are grossly insufficient to draw inferences about the origin of SARS-CoV-2. De-novo assembly, KRONA analysis for metagenomic and re-examining data quality highlights the key issues with the RaTG13 genome and the need for a dispassionate review of this data. This work is a call to action for the scientific community to better collate scientific evidence about the origins of SARS-CoV-2 so that future incidence of such pandemics may be effectively mitigated.
REVIEW | doi:10.20944/preprints202004.0383.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; coronavirus pandemic; big data; epidemic outbreak; artificial intelligence (AI); deep learning
Online: 21 April 2020 (09:01:45 CEST)
The very first infected novel coronavirus case (COVID-19) was found in Hubei, China in Dec. 2019. The COVID-19 pandemic has spread over 215 countries and areas in the world, and has significantly affected every aspect of our daily lives. At the time of writing this article, the numbers of infected cases and deaths still increase significantly and have no sign of a well-controlled situation, e.g., as of 14 April 2020, a cumulative total of 1,853,265 (118,854) infected (dead) COVID-19 cases were reported in the world. Motivated by recent advances and applications of artificial intelligence (AI) and big data in various areas, this paper aims at emphasizing their importance in responding to the COVID-19 outbreak and preventing the severe effects of the COVID-19 pandemic. We firstly present an overview of AI and big data, then identify their applications in fighting against COVID-19, next highlight challenges and issues associated with state-of-the-art solutions, and finally come up with recommendations for the communications to effectively control the COVID-19 situation. It is expected that this paper provides researchers and communities with new insights into the ways AI and big data improve the COVID-19 situation, and drives further studies in stopping the COVID-19 outbreak.
ARTICLE | doi:10.20944/preprints202006.0129.v1
Online: 10 June 2020 (09:22:11 CEST)
The emergence of COVID -19 pandemic has severely impacted individuals from all walks of life. The rapid spread of the disease to nearly all parts of the country has posed enormous health, economic, environmental and social challenges to the entire human population. In the absence of any effective drugs and vaccines for treatment, social distancing and other preventive measures are the only alternatives. Lockdown is among one of the options suggested by WHO to reduce spread of the virus. India was quick to close its international borders and enforce the world’s largest COVID lockdown on March 22, 2020. The present study attempts to highlight the impact of imposed nationwide lockdown on society and environment alike along with analysis of lifestyle changes. The study was based on an online survey using a structured questionnaire with over 1000 responders across the country. The pandemic situation demands a certain way of shaping the society to reduce virus spread and safeguard oneself. In this study, we analysed the changes that the society has undergone during lockdown to mitigate the spreading of the infection. We also addressed the changes that have become part of our lives during lockdown – hygiene and health consciousness, work from home (WFM), online teaching, digital shopping, changing internet habits and societal changes.
ARTICLE | doi:10.20944/preprints202003.0360.v2
Subject: Life Sciences, Genetics Keywords: SARS-CoV-2; transcriptional inhibition; COVID-19; drug repurposing; TMPRSS2
Online: 28 April 2020 (09:39:02 CEST)
There is an urgent need to identify effective therapies for COVID-19. The SARS-CoV-2 host factor protease TMPRSS2 is required for viral entry and thus an attractive target for therapeutic intervention. In mouse, knockout of tmprss2 led to protection against SARS-CoV-1 with no deleterious phenotypes, and in human populations genetic loss of TMPRSS2 does not appear to be selected against. Here, we mined publicly available gene expression data to identify several compounds that down-regulate TMPRSS2. Recognizing the need for immediately available treatment options, we focused on FDA-approved drugs. We found 20 independent studies that implicate estrogenic and androgenic compounds as transcriptional modulators of TMPRSS2, suggesting these classes of drugs may be promising therapeutic candidates for clinical testing and observational studies of COVID-19. We also note that expression of TMPRSS2 is highly variable and skewed in humans, with a minority of individuals having extremely high expression. Combined with literature showing that inhibition of TMPRSS2 protease activity reduces SARS-CoV-2 viral entry in human cells, our results raise the hypothesis that modulation of TMPRSS2 expression is a promising therapeutic avenue for COVID-19.
ARTICLE | doi:10.20944/preprints202002.0220.v2
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: coronavirus; COVID-19 pneumonia; pathology; SARS-CoV-2
Online: 2 March 2020 (01:34:58 CET)
There is currently a lack of pathologic data on the novel coronavirus (SARS-CoV-2) pneumonia, or COVID-19, from autopsy or biopsy. Two patients who recently underwent lung lobectomies for adenocarcinoma were retrospectively found to have had COVID-19 at the time of surgery. These two cases thus provide important first opportunities to study the pathology of COVID-19. Pathologic examinations revealed that, apart from the tumors, the lungs of both patients exhibited edema, proteinaceous exudate, focal reactive hyperplasia of pneumocytes with patchy inflammatory cellular infiltration, and multinucleated giant cells. Hyaline membranes were not prominent. Since both patients did not exhibit symptoms of pneumonia at the time of surgery, these changes likely represent an early phase of the lung pathology of COVID-19 pneumonia.
Subject: Life Sciences, Immunology Keywords: immune system; viral infection; influenza; COVID-19; micronutrients; vitamins; omega-3 fatty acids; minerals; vitamin C; vitamin D
Online: 12 March 2020 (04:30:45 CET)
Public health practices including handwashing and vaccinations help reduce the spread and impact of infections. Nevertheless, the global burden of infection is high, and additional measures are necessary. Acute respiratory tract infections, for example, are responsible for approximately 2.65 million deaths per year. The role nutrition plays in supporting the immune system is well-established. A wealth of mechanistic and clinical data show that vitamins, including vitamins A, B6, B12, C, D, E, and folate; trace elements, including zinc, iron, selenium, magnesium, and copper; and the omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid play important and complementary roles in supporting the immune system. Inadequate intake and status of these nutrients are widespread, leading to a decrease in resistance to infections and as a consequence an increase in disease burden. Against this background the following conclusions are made: 1) Supplementation with the above micronutrients and omega-3 fatty acids is a safe, effective, and low-cost strategy to help support optimal immune function; 2) Supplementation above the RDA, but within recommended upper safety limits, for specific nutrients such as vitamins C and D is warranted; and 3) Public health officials are encouraged to include nutritional strategies in their recommendations to improve public health.
BRIEF REPORT | doi:10.20944/preprints202003.0295.v1
Subject: Medicine & Pharmacology, Other Keywords: Wuhan 2019-nCoV; ACE2; DNA methylation; epigenetics; profiling; lung tissue; age; gender; COVID-19; coronavirus
Online: 19 March 2020 (02:51:45 CET)
Background: Coronavirus disease 2019 (COVID-19) has emerged as a global threat to human health and disease risk increases with advancing age. The regulation of the ACE2 gene that codes for COVID-19 host receptor ACE2 has been shown to be under epigenetic regulation. Here, we examined whether intensive DNA methylation profiling of the ACE2 gene differed by human host tissue and cell type, gender, and age. Results: Accessing four public datasets, we observed unique human cell-type-specific ACE2 DNA methylation patterns. In human lung tissues, gender differences in DNA methylation at 2 sites related to the ACE2 gene were identified. Further, in freshly isolated airway epithelial cells, DNA methylation near the transcription start site of the ACE2 gene associated with biological age. Conclusion: Epigenetic profiling of host tissue may permit discovery of age and gender-related potential risk factors for COVID-19. How perturbations in ACE2 methylation relate to clinical severity across the ages and gender needs to be determined to guide screening tools and potential epigenetic modification targeting to alleviate COVID-19 morbidity in the elderly.
ARTICLE | doi:10.20944/preprints202008.0267.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; intensive care; trends; United Kingdom; mortality; mechanical ventilation
Online: 9 September 2020 (09:28:49 CEST)
Rationale: Examining trends in patient characteristics, processes of care and outcomes, across an epidemic, provides important opportunities for learning. Objectives: To report and explore changes in admission rates, patient characteristics, processes of care and outcomes for all patients with COVID-19 admitted to intensive care units (ICUs) in England, Wales and Northern Ireland. Methods: Population cohort of 10,287 patients with COVID-19 in the Case Mix Programme national clinical audit from 1 February to 2 July, 2020. Analyses were stratified by time period (pre-peak, peak, post-peak) and geographical region. Multivariable logistic regression was used to estimate differences in 28-day mortality, adjusting for patient characteristics over time. Main results: Admissions to ICU peaked simultaneously across regions on 1 April, with ongoing admissions peaking ten days later. Compared with pre- and post-peak periods, patients admitted during the peak were slightly younger but had greater respiratory and renal dysfunction. Use of invasive ventilation and renal replacement reduced over time. Twenty-eight-day mortality reduced from 43.5% (95% CI 41.6% to 45.5%) pre-peak to 34.3% (95% CI 32.3% to 36.2%) post-peak; a difference of −8.8% (95% CI: −5.2%, −12.3%) after adjusting for patient characteristics. London experienced the highest admission rate and had higher mortality during the peak period but a greater reduction in post-peak mortality. Conclusion: This study highlights changes in patient characteristics, processes of care and outcomes, during the UK COVID-19 epidemic. After adjusting for the changes in patient characteristics and first 24-hour physiology, there was substantial improvement in 28-day mortality over the course of the epidemic.
CASE REPORT | doi:10.20944/preprints202008.0640.v1
Subject: Medicine & Pharmacology, Other Keywords: VIP; COVID-19; respiratory failure; vasoactive intestinal peptide; aviptadil; ARDS
Online: 28 August 2020 (11:38:23 CEST)
Background: Vasoactive Intestinal Peptide (VIP) is known to bind to and protect the Alveolar Type II cell by blocking replication of the SARS-CoV-2 virus, upregulating surfactant production, blocking apoptosis, and blocking cytokine effects. RLF-100 (Aviptadil), a synthetic form of Vasoactive Intestinal Peptide (VIP) has been granted Fast Track Designation and is currently in phase 2/3 placebo-controlled trials. FDA has granted Emergency Use IND and Expanded Access Protocol approval for the use of RLF-100 in patients whose comorbidities render them ineligible for inclusion in the ongoing pivotal trial. Methods: This report describes the first 6 patients with Acute Respiratory Failure in Critical COVID-19, enrolled under Emergency Use IND were treated with three successive 12-hour infusions of intravenous Aviptadil at 50/100/150 pmol/kg/hr, while continuing to receive maximal ICU care. Results: Median patient follow-up time is 14 days. So far, all treated patients have survived. Improved radiographic appearance of typical “ground glass” COVID-19 features to varying degrees is seen in all patients within 72 hours. Improvement in blood oxygenation is seen in all patients, with complete remission from respiratory failure in 4 of 6 patients. An average 56% reduction in inflammatory markers was seen, together with a median 4 point reduction in the NIAID Ordinal Scale. 2/6 patients were discharged from the hospital and 1 patient was downgraded to the general medicine floor. Comment: The short term survival of 6/6 patients with respiratory failure in the setting of COVID-19 and major comorbidity is the most dramatic response ever seen with an antiviral agent. Improvement in radiographic appearance, oxygenation requirement, and inflammatory markers is consistent with in vitro evidence of direct anti-viral effect.
ARTICLE | doi:10.20944/preprints202102.0264.v1
Subject: Keywords: SARS-CoV-2, RaTG13, Furin Site, Molecular Evolution, Bioinformatics.
Online: 10 February 2021 (15:46:12 CET)
The SARS-CoV-2 high infectivity is due to the functional polybasic furin cleavage site in the S protein. How it was acquired is unknown. There are two challenges to face: (i) an evolutionary model, to fit the origin of the coronavirus; and (ii) a molecular mechanism for the site acquisition. Here we show genomic fingerprints which are specific of Pangolin-CoVs, Bat-SARS-like (CoVZC45, CoVZXC21), bat RatG13 and human SARS-CoV-2 coronaviruses. This, along with phylogenetic analysis, we found that these species have the same evolutionary origin in the bat, including a genetic recombination of S gene between Pangolin-CoV (2017) and RatG13 ancestors. However, this does not explain why SARS-CoV-2 is the only of them with the furin site, which consists in four amino acid (PRRA) motif. The Arginine doublet is encoded by CGGCGG codons. Surprisingly, none of the Arginine doublet of other furin site of viral proteins from several type of viruses, are encoded by the CGGCGG codons. This makes it difficult to consider a virus recombination as mechanism for the PRRA acquisition. The origin of SARS-CoV-2, is the origin of the recognition cleavage site. The bat coronavirus RaTG13 appears to be the closest relative of the SARS-CoV-2, but was isolated in 2013. So, new RatG13 samples would provide insights into the acquisition of the polybasic motif.
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.
Subject: Engineering, Electrical & Electronic Engineering Keywords: coronavirus; COVID-19; diagnosis; deep features; SVM
Online: 22 April 2020 (05:58:22 CEST)
The detection of coronavirus (COVID-19) is now a critical task for the medical practitioner. The coronavirus spread so quickly between people and approaches 100,000 people worldwide. In this consequence, it is very much essential to identify the infected people so that prevention of spread can be taken. In this paper, the deep feature plus support vector machine (SVM) based methodology is suggested for detection of coronavirus infected patient using X-ray images. For classification, SVM is used instead of deep learning based classifier, as the later one need a large dataset for training and validation. The deep features from the fully connected layer of CNN model are extracted and fed to SVM for classification purpose. The SVM classifies the corona affected X-ray images from others. The methodology consists of three categories of Xray images, i.e., COVID-19, pneumonia and normal. The method is beneficial for the medical practitioner to classify among the COVID-19 patient, pneumonia patient and healthy people. SVM is evaluated for detection of COVID-19 using the deep features of different 13 number of CNN models. The SVM produced the best results using the deep feature of ResNet50. The classification model, i.e. ResNet50 plus SVM achieved accuracy, sensitivity, FPR and F1 score of 95.33%,95.33%,2.33% and 95.34% respectively for detection of COVID-19 (ignoring SARS, MERS and ARDS). Again, the highest accuracy achieved by ResNet50 plus SVM is 98.66%. The result is based on the Xray images available in the repository of GitHub and Kaggle. As the data set is in hundreds, the classification based on SVM is more robust compared to the transfer learning approach. Also, a comparison analysis of other traditional classification method is carried out. The traditional methods are local binary patterns (LBP) plus SVM, histogram of oriented gradients (HOG) plus SVM and Gray Level Co-occurrence Matrix (GLCM) plus SVM. In traditional image classification method, LBP plus SVM achieved 93.4% of accuracy.
CONCEPT PAPER | doi:10.20944/preprints202104.0633.v1
Subject: Medicine & Pharmacology, Allergology Keywords: viral transmission; causation; evidence hierarchy; SARS-CoV-2; respiratory pathogens
Online: 23 April 2021 (11:59:58 CEST)
We propose a hierarchical framework based on our experience of systematically reviewing and synthesizing 378 primary studies for an evidence-based update of the modes of transmission for SARS-CoV-2. These studies revealed significant methodological shortcomings with a lack of standardization in the design, conduct, testing and reporting of SARS-CoV-2 transmission. While this situation is in part excusable at the outset of a pandemic, evidence rules of proof for assessing the transmission of this virus are needed for this and future pandemics of viral respiratory pathogens. We review the history of causality assessment related to microbial etiologies with a focus on respiratory viruses and suggest a hierarchy of evidence to integrate clinical, epidemiologic, molecular and laboratory perspectives on transmission. The hierarchy, if applied to future studies, should narrow the uncertainty over the twin concepts of causality and transmission of human respiratory viruses. We attempt to address the translational gap between the current research evidence and the assessment of causality in the transmission of respiratory viruses with a focus on SARS-CoV-2. Experimentation, consistency and independent replication of research alongside our proposed framework provide a chain of evidence that can reduce the uncertainty over the transmission of respiratory viruses and increase the level of confidence in specific modes of transmission and the measures that should be undertaken to prevent transmission
COMMUNICATION | doi:10.20944/preprints202003.0445.v1
Subject: Social Sciences, Geography Keywords: international tourism; coronavirus; COVID-19; post-viral tourism; recovery strategies
Online: 31 March 2020 (05:00:08 CEST)
The coronavirus pandemic will deeply affect the tourism and travel sector. It is already clear now that its economic impact would be more severe that in the case of the Severe Acute Respiratory Syndrome (SARS) in 2002-2003. Although not as deadly as SARS, coronavirus infection has a longer incubation period and leaves about 85% of the infected without any (or with just mild) symptoms which makes it more difficult to track and to contain. Moreover, it appears to be much more contagious than its predecessor. The goods news is that most people recover from the disease and develop antibodies that can protect them from getting infected again (natural vaccination). Those cured might become the key element for the post-virus recovery strategies of tourism organisations. People with the acquired immunity to the virus would be capable of travelling freely without spreading the disease. Airlines, hotels and gastronomy should aim at this group offering them discounts and special offers. However, the problem is how to effectively ensure that everyone who claims to be cured from COVID-19 is telling the truth. Health tracking bracelets, apps, and other advanced technological solutions should be put in place. Recent best practices from Hong Kong, mainland China, or India might be applied.
HYPOTHESIS | doi:10.20944/preprints202004.0143.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: SARS-CoV-2; COVID-19; IL-6; inflamm-aging; immune senescence; host-directed therapies
Online: 9 April 2020 (08:38:22 CEST)
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is characterized by a high mortality of elderly men with age-related comorbidities. In most of these patients, uncontrolled local and systemic hyperinflammation induces severe and often lethal outcomes. The aging process is characterized by the gradual development of a chronic subclinical systemic inflammation (inflamm-aging) and by acquired immune system impairment (immune senescence). Here, we advance the hypothesis that some key features of aging contribute to the disproportionate SARS-CoV-2 mortality suffered by elderly men. At least four well-recognized aging-related characteristics that are strongly expressed in older men go some way towards explaining why these patients account for the vast majority of fatalities: i. the presence of subclinical systemic inflammation without overt disease, ii. a blunted acquired immune system and type I interferon response due to the chronic inflammation; iii. the downregulation of ACE2 (SARS-CoV-2 receptor), which triggers inflammation, particularly in patients with age-related comorbid diseases such as type II diabetes; and iv. accelerated biological aging, as measured by epigenetic and senescence markers (e.g. telomere shortening) associated to the chronic inflammatory state. Though typical of the aged, especially of elderly men, it is conceivable that these features are also shared by some subsets of the younger population. The high mortality rate of SARS-CoV-2 infection suggests that clarification of the mechanisms of inflamm-aging and immune senescence can help combat not only age-related disorders but also SARS-CoV-2 infection.
ARTICLE | doi:10.20944/preprints202102.0590.v1
Subject: Keywords: African swine fever virus (ASFV); Pork shortage; Alternative meat consumption; Wildlife; Human-animal contact; Zoonotic spillover; SARS-CoV-2
Online: 25 February 2021 (16:57:13 CET)
The spillover of a virus from one host species to another requires both molecular and ecological risk factors to align. While extensive research both before and after the emergence of SARS-CoV-2 in 2019 implicates horseshoe bat as the significant reservoir genus for the new coronavirus, it remains unclear why it emerged at this time. One massive disruption to human-animal contact in 2019 is linked to the on-going African swine fever virus (ASFV) pandemic. This began in Georgia in 2007 and was introduced to China in 2018. Pork is the major meat source in the Chinese diet. Severe fluctuations in the pork market prior to December 2019, may have increased the transmission of zoonotic pathogens, including severe acute respiratory syndrome–related coronaviruses, from wildlife to humans, wildlife to livestock and non-local animals to local animals. The major production and consumption regions for pork are geographically separated in China. The dramatic shortage of pork following restrictions of pig movement and culling resulted in price increases, leading to alternative sources of meat and unusual animal and meat movements nationwide often involving wildlife and thus greatly increased opportunities for human-Sarbecovirus contacts. Pork prices were particularly high in southern provinces (Guangdong, Guangxi, Fujian, Jiangxi, Hunan, and Hubei), where wildlife is farmed on different scales and more frequently consumed. Shandong experienced the biggest losses in pork production (~1.7 million metric tons), which is also the largest mink farming province. Hence, human exposure to SARS-CoV-2 from wildlife or infected animals are more likely to have taken place in 2019, when China was experiencing the worst effects of the ASFV pandemic.
Online: 16 October 2020 (11:49:13 CEST)
Coronavirus disease 2019 (COVID-19) is caused by infection with the 2019 novel coronavirus 2 (2019-nCoV, now referred to as SARS-CoV-2). COVID-19 has become a global pandemic since its outbreak at the end of Dec 2019. COVID-19 could lead to severe acute respiratory disease, especially to those who have reduced immunity. Binding of the viral Spike protein (S) to its receptor ACE2 (Angiotensin Converting Enzyme 2) on the surface of target cells has been proven to be key for virus entry and infection. Although ACE2 expression in the respiratory system is necessary for pneumonia infection by SARS-CoV-2, the regulation of ACE2 gene expression remains poorly investigated, especially for patients that are in pre-pathological conditions. Here, by analyzing The Gene Expression Omnibus (GEO) database, we investigated the expression regulation of ACE2 in various kinds of primary epithelial cells from the respiratory system after varies of respiratory viruses infection such as influenza A virus (IFV), respiratory syncytial virus (RSV) and human rhinovirus (hRV). Our analyses reveal that infection of multiple kinds of respiratory viruses or influenza vaccines greatly increased ACE2 expression, suggesting that respiratory viruses infection could represent a high risk factor for developing COVID-19. We also found that the regulatory effect of influenza A virus on ACE2 expression is associated with activation of the interferon beta-induced pathway and viral RNA-activated host response. Together, our data provide a theoretical framework for clinical classification for SARS-CoV-2 infection susceptibility and could be used for future prevention and therapy treatment for COVID-19.
ARTICLE | doi:10.20944/preprints202003.0444.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: COVID-19; SARS-CoV-2; coronavirus; novel coronavirus; 3D printing; N95; respirator; mask
Online: 31 March 2020 (04:44:06 CEST)
The 2019 Novel Coronavirus (COVID-19) has caused an acute reduction in world supplies of personal protective equipment (PPE) due to increased demand. To combat the impending shortage of equipment including N95 masks, the George Washington University Hospital (GWUH) developed a 3D printed reusable N95 comparable respirator that can be used with multiple filtration units. We evaluated several candidate prototype respirator models, 3D printer filaments, and filtration units detailed here. Our most recent working model was based on a respirator found on an open source maker website and was developed with PLA (printer filament), a removable cap, a removable filtration unit consisting of two layers of MERV 16 sandwiched between MERV 13, and removable elastic bands to secure the mask. Our candidate mask passed our own suction test protocol to evaluate leakage and passed a qualitative Bitrix N95 fit test at employee health at GWUH. Further efforts are directed at improving the current model for seal against face, comfort, and sizing. The 3D model is available upon request and in the supplement of this paper. We welcome collaboration with other institutions and suggest other facilities consider mask fit for their own population when exploring this concept.
REVIEW | doi:10.20944/preprints202004.0283.v1
Subject: Medicine & Pharmacology, Other Keywords: Covid-19; coronavirus; SARS-CoV-2; review; pandemic
Online: 16 April 2020 (15:55:12 CEST)
Coronaviruses are an extensive family of viruses that can cause disease in both animals and humans. The current classification of coronaviruses recognizes 39 species in 27 subgenera that belong to the family Coronaviridae. From those, at least seven coronaviruses are known to cause respiratory infections in humans. Four of these viruses can cause common cold-like symptoms, while others that infect animals can evolve and become infectious to humans. Three recent examples of this viral jumps include SARS CoV, MERS-CoV and SARS CoV-2 virus. They are responsible for causing severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS) and the most recently discovered coronavirus disease during 2019 (COVID-19).COVID-19, a respiratory disease caused by the SARS-CoV-2 virus, was declared a pandemic by the World Health Organization (WHO) on 11 March 2020. The rapid spread of the disease has taken the scientific and medical community by surprise. Latest figures from 14 April 2020 show more than 2 million people had been infected with the virus, causing more than 120,000 deaths in over 210 countries worldwide. The large amount of information we receive every day concerning this new disease is so abundant and dynamic that medical staff, health authorities, academics and the media are not able to keep up with this new pandemic. In order to offer a clear insight of the extensive literature available, we have conducted a comprehensive literature review of the SARS CoV-2 Virus and the Coronavirus Diseases 2019 (COVID-19).
REVIEW | doi:10.20944/preprints202009.0395.v1
Subject: Life Sciences, Virology Keywords: Spike protein, V483A, substitution mutation, virus-host cell interaction, high transmission, infectivity.
Online: 17 September 2020 (10:43:02 CEST)
Exploring the biological significance of mutations in SARS-CoV-2 coronavirus, causing the COVID–19 pandemic, has recently become an area of paramount interest for many researchers, who are pouring their tremendous efforts, in cracking the COVID–19 pandemic code. One of many such mutations that have occurred in the viral genome is V483A mutation, which is a part of the receptor-binding motif (RBM), present in the S1 domain of the spike protein. V483A mutant virus is becoming popular in North America with 36 cases so far, due to its frequent occurrences in recent days. In this review, we have assembled all information, currently available on V483A mutation, and have made a critical analysis based on the perspectives of many researchers all around the world. Comparison is made between the wild type and the V483A mutants to analyze certain factors like the type of interaction between the virus and host cell interface, binding affinity, stability, partition energy, hydrophobicity, occurrence rate, and transmissibility. Insilico dynamic analysis shows minimal alteration in the receptor-binding domain (RBD) of V483A mutant protein in free-state and no significant change of mutant tertiary structure of RBM upon binding to the ACE2 receptor. Comprehensive details about infectivity and evasion of the immune system by the virus are discussed. This information can in turn be of monumental importance in the field of vaccine and drug development because the mutants are becoming resistant to the vaccines and monoclonal antibodies.
ARTICLE | doi:10.20944/preprints202005.0301.v1
Subject: Keywords: COVID-19; SARS-CoV-2; smoking; nicotine; nicotinic cholinergic system; inflammation
Online: 18 May 2020 (11:51:44 CEST)
Smoking is a risk factor for respiratory infections and there is reasonable concern that it may affect COVID-19 susceptibility and severity. Recent studies have focused on the interaction between smoking (and nicotine) and ACE2 expression, suggesting that ACE2 up-regulation could contribute to enhanced viral cell entry. However, case series have shown that there is an unexpectedly low prevalence of smoking among hospitalized COVID-19 cases. Since early April, we were the first to hypothesize that dysfunction of the nicotinic cholinergic system (NCS) may be implicated in the pathophysiology of severe COVID-19. We recently reported that many of the clinical manifestations of severe COVID-19 could be explained by dysregulation of the NCS. In this study, we present an amino acid sequence in the receptor binding domain of the SARS-CoV-2 Spike glycoprotein which is homologous to a sequence of a snake venom toxin. We present the 3D structural location of this “toxin-like” sequence on the Spike Glycoprotein. These findings suggest that SARS-CoV-2 could potentially interact with acetylcholine receptors causing dysregulation of the NCS and the cholinergic anti-inflammatory pathway.
COMMUNICATION | doi:10.20944/preprints202003.0184.v2
Subject: Medicine & Pharmacology, Other Keywords: SARS-CoV-2; diagnosis; antibody; serology; screening
Online: 6 April 2020 (14:09:34 CEST)
To date, viral RNA detection is almost the only way to confirm SARS-CoV-2infectionin practice.However, variousreasons can cause low sensitivity for RNA detection, and thisposes aserious challenge to disease control. We tested the performance of detecting total antibody(Ab) and IgM levels in serum by the methods of chemiluminescence, enzyme-linked immunosorbent assay (ELISA), and colloidal golddetection. The datashowed that the sensitivity and specificity for detecting total Ab and IgM levels were high by all three methods, and the sensitivity was higher for detecting total Ab than for detecting IgM. Evidence from studieshas shown thatviral RNA testingcombinedwith serological testing could increase the diagnostic sensitivity while maintaining a high specificity. Specific serology testsfor SARS-CoV-2 havegreat value for clinical practice and public health.
REVIEW | doi:10.20944/preprints202004.0122.v2
Subject: Life Sciences, Immunology Keywords: melatonin; coronavirus; pandemic; SARS-CoV-2; bat; lung; apoptosis; programmed cell death; mortality; morbidity; COVID-19; drug
Online: 9 April 2020 (09:24:47 CEST)
The current COVID-19 pandemic is one of the most devastating events in recent history. The virus causes relatively minor damage to young, healthy populations, imposing life-threatening danger to the elderly and people with diseases of chronic inflammation. Therefore, if we could reduce the risk for vulnerable populations, it would make the COVID-19 pandemic more similar to other typical outbreaks. Children don’t suffer from COVID-19 as much as their grandparents and have a much higher melatonin level. Bats are nocturnal animals possessing high levels of melatonin, which may contribute to their high anti-viral resistance. Viruses induce an explosion of inflammatory cytokines and reactive oxygen species, and melatonin is the best natural antioxidant that is lost with age. The programmed cell death coronaviruses cause, which can result in significant lung damage, is also inhibited by melatonin. Coronavirus causes inflammation in the lungs which requires inflammasome activity. Melatonin blocks these inflammasomes. General immunity is impaired by anxiety and sleep deprivation. Melatonin improves sleep habits, reduces anxiety and stimulates immunity. Fibrosis may be the most dangerous complication after COVID-19. Melatonin is known to prevent fibrosis. Mechanical ventilation may be necessary but yet imposes risks due to oxidative stress, which can be reduced by melatonin. Thus, by using the safe over-the-counter drug melatonin, we may be immediately able to prevent the development of severe disease symptoms in coronavirus patients, reduce the severity of their symptoms, and/or reduce the immuno-pathology of coronavirus infection on patients’ health after the active phase of the infection is over.
Subject: Medicine & Pharmacology, Nursing & Health Studies Keywords: 2019-nCoV; epidemiology; causes; prevention and control; review
Online: 6 February 2020 (08:54:11 CET)
The 2019-nCoV has been identified as the cause of an outbreak of respiratory illness in Wuhan, Hubei Province, China beginning in December 2019. This epidemic had spread to 19 countries with 11,791 confirmed cases, including 213 deaths, as of January 31, 2020. The World Health Organization declared it as a Public Health Emergency of International Concern. This study analyzed and discussed 70 research articles published until January 31, 2020 for a better understanding of the epidemiology, causes, clinical diagnosis, prevention and control of this virus. Studies thus far have shown origination in connection to a seafood market in Wuhan, but specific animal association has not been confirmed. The reported symptoms include fever, cough, fatigue, pneumonia, headache, diarrhea, hemoptysis, and dyspnea. Preventive measures such as masks, hand hygiene practices, avoidance of public contact, case detection, contact tracing, and quarantines are effective for reducing the transmission. To date, no specific antiviral treatment is proven effective, hence, infected people primarily rely on symptomatic treatment and supportive care. Although these studies had relevance to control a public emergency, more research need to be conducted to provide valid and reliable ways to manage this kind of public health emergency in both short- and long- term.
Online: 26 September 2020 (13:08:55 CEST)
The issues mothers face in the academy have been discussed for decades. Routinely, new studies report significant differences between women and men at comparable career stages with respect to salary, service demands, publications, grant submissions, and overall funding rates. The COVID-19 pandemic is further exposing these inequalities as women scientists who are parenting while also engaging in a combination of academic related duties are falling further behind. COVID-19 is shaking the very foundations of our society and laying bare the many inequalities that defined our pre-COVID world. We can solve these inequities by investing strategically in creative solutions, thereby making the most of women’s contributions to scientific endeavors. Here we describe strategies that would make the academy more equitable for working mothers now and into the future. Importantly, while the data are clear that mothers are being disproportionally impacted by COVID-19, many groups could benefit from these same ideas. Now is the time to act. Rather than rebuilding what we once knew, let us be the architects of a new world.
Subject: Life Sciences, Biotechnology Keywords: SARS-CoV-2; COVID-19; acute kidney injury; angiotensin converting enzyme II (ACE2); transmembrane serine protease (TMPRSSs)
Online: 23 February 2020 (15:42:24 CET)
Purpose: Acute kidney injury (AKI) is a severe symptom of the 2019 novel coronavirus disease (COVID-19), especially for patients in a critical condition.This study explored the potential mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on AKI at the single-cell level. Methods: 15 normal human kidney samples were collected and analyzed using single-cell RNA sequencing (scRNA-seq). Subsequently, we analyzed the components and proportions of kidney cells expressing the host cellular receptor ACE2 and the key protease TMPRSSs family, and analyzed the expression differences in Occidental and Asian populations. Results: We drafted the currently available world's largest human kidney cell atlas with 42,589 cells and identified 19 clusters through unsupervised hierarchical clustering analysis. ACE2 and TMPRSSs genes were significantly co-expressed in podocytes and proximal convoluted tubules as potential host cells targeted by SARS-CoV-2. Comparative analysis showed that ACE2 expression in kidney cells was no less than that in the lung, esophagus, small intestine and colon, suggesting that the kidney may be an important target organ for SARS-CoV-2. In addition, given the high expression of ACE2 and kidney disease-related genes in Occidental donors relative to Asian donors, Occidental populations with SARS-CoV-2 infection might be a higher risk of of kidney injury.
ARTICLE | doi:10.20944/preprints202002.0438.v1
Subject: Chemistry, Medicinal Chemistry Keywords: COVID-19; Simeprevir; Protease inhibitor; Virtual screening; Docking
Online: 28 February 2020 (13:14:38 CET)
Coronavirus disease 2019 (COVID-19) has been first appeared in Wuhan, China but its fast transmission, led to its widespread prevalence in various countries and make it a global concern. In addition, lack of a definitive treatment is another concern that needs to be attention. Researchers have come up with several options, which are not certain, but protease inhibitor and some antiviral agent are in the forefront. In this study a virtual screening procedure employing docking of different databases including 1615 FDA approved drugs was used to identify new potential small molecule inhibitors for protease protein of COVID-19. The docking result indicates that among all, simeprevir (Hepatitis C virus (HCV) NS3/4A protease inhibitor) could fit well to the binding pocket of protease and because of some other positive features including ADME profile, might be a helpful treatment option for COVID-19.