Vaccination is the most promising approach for ending or containing the SARS-CoV2 pandemic. However, serious post-COVID vaccine reactions including immunocytopenia (ITP) syndrome has been increasingly reported. Several factors cause increased risks including multiple doses, age-dependent heterogeneity in immune-responses, platelet cross-reactions with microbial components, and Long-COVID syndrome. Thus, in the absence of a widely available specific therapeutics, vigilance is important while more studies are imperative. Using a structured questionnaire sent to different regions in Saudi Arabia, we conducted a comprehensive investigation on the frequency, rates, disease patterns, and patient demographics of post-COVID-19 side effects on febrile patients after three major vaccines. Results indicated the majority administered Pfizer BioNtech vaccine (81%, n=809); followed by AstraZeneca (16%, n=155); and Moderna (3%, n=34). In overall 998 participants, 74% (n=737) had no serious symptoms; however, 26.2% (n=261) revealed typical syndrome. In a focused group of 722, shortness of breath (20%), bruises or bleeding (18%), inattention (18%), GIT symptoms (17.6%), skin irritation (8.6%), and anosmia and ageusia (8%) were the most prominent. The onset time was mostly in 1-3 days in 49% (n=128), followed by 4-7 days in 21.8% (n=57), 8-14 days in 16.5% (n=43), and more than a month in 12.6% (n=33). The onsets occurred mostly after the first, second, or both doses 9%, 10%, and 7%, respectively. The frequency of symptoms was significantly higher among after Moderna ® vaccine (P-value = 0.00006) and it was significantly lower in participants who received Pfizer (P-value 0.00231). We did not find significant difference in symptoms related to differences in regions. Similarly, the region, age, gender, education, and nationality had no influence in the dose and onset timings. The findings of this study have significant clinical implications in disease management strategies, preventive measures, and vaccine development. Future vertical studies would reveal more insights into the mechanisms of post-COVID vaccine syndrome.

Introduction.Sars-CoV-2 infection poses particular problems in pregnancy, as the infection more frequently causes severe complications than in unaffected pregnant women, or non-pregnant women with SARS-CoV-2 infection. Now that vaccination is available and rapidly getting implemented worldwide, the question arises whether pregnant women should be vaccinated, and if so, whether they should get priority. Methods. Available scientific data and available guidelines about vaccination against SARS-CoV-2 were collected by the Guideline Committee of the International Society of Infectious Diseases in Obstetrics and Gynecology (ISIDOG), and were analyzed, discussed and summarized as guidelines for health care workers caring for pregnant women. Concluding statements were graded according to the Oxford Evidence Based Medicine Grading System. Results. There is evidence to consider pregnancy as a risk factor for serious complications of COVID-19 infection, even in the absence of additional risk factors, such as hypertension, diabetes and obesity which increase these risks even more in pregnancy. Currently available data slightly favor mRNA-based vaccines above vector-based vaccines during pregnancy and breastfeeding, until more safety data become available. Conclusion. ISIDOG advices policy makers and societies to prioritize pregnant women to receive vaccination against SARS-CoV-2, and favor the mRNA vaccines until further safety information becomes available.

To date, the impact of COVID-19 vaccination on formerly menstruating women remains unknown. For this reason, a retrospective observational cross-sectional study was conducted (N= 548) using an online survey. General characteristics, medical history, and adverse events following COVID-19 vaccination were recorded. In comparison with the first dose, significantly higher percentages of respondents experienced menstrual-related disturbances (dose 1: 38.5% vs. dose 2: 44.8%; McNemar=9.15; mid P-value=0.002), as well as the simultaneous occurrence of two or more of these symptoms (dose 1: 11.2% vs. dose 2: 15.3%; McNemar=13.53; mid P-value=0.044) after receiving the second one. Among them, those related with the length and flow stand out, being of long-term nature in about 17-20% of cases. Interindividual factors influencing this unexpected event after receiving the dose 1 may include weight (AOR 1.02, CI 95% 1.01–1.03, P<.001), perimenopause (AOR 2.28, CI 95% 1.37–3.77, P=.001), pre-existing diagnoses of non-autoimmune rheumatic/articular conditions (AOR 0.31, CI 95% 0.10–1.00, P=0.05), hormonal contraceptive use (AOR 0.25, CI 95% 0.07-0.82, P=0.02), suffering from other vaccine side effects − such as arm pain (AOR 0.61, CI 95% 0.39–0.95, P=0.03), headache (AOR 0.53, CI 95% 0.35 – 0.80, P=.003), swollen glands (AOR 0.29, CI 95% 0.15 – 0.60, P=.001) and nauseas (AOR 0.35, CI 95% 0.14 – 0.86, P=0.02) – and the number of previous pregnancies (AOR 2.70, CI 95% 1.54 – 4.76, P=.001). Formerly menstruating women may experience long-term menstrual-related disturbances following COVID-19 vaccination.

Tetanus toxoid (TT) vaccination during pregnancy has been proven as an effective preven-tive measure to reduce the incidence of maternal and neonatal morbidity and mortality worldwide. This study aimed to assess the determinants of TT vaccine uptake among pregnant women in two public maternity specialized hospitals in Sudan. A hospi-tal-based cross-sectional study was conducted in two public hospitals, Omdurman Ma-ternity and AL-Saudi hospitals in Omdurman, Khartoum State in Sudan, from February to April 2020. Logistic regression analysis was carried out to identify factors associated with receiving three or more doses of TT vaccine among pregnant women (protected against tetanus), presented as Odds ratios, with p-values <0.05 considered significant (at 95% confidence interval). The study recruited 350 pregnant women, with 313 participants in-cluded in the analysis. This study found that only 40% of the pregnant women received 3 doses or more (protected) of TT vaccine during their current pregnancy. Pregnant women who attended Al Saudi hospital were less likely to be protected against Tetanus (received ≥ 3 doses) compared to those who attended Omdurman hospital [OR= 0.49 (95%C.I 0.29-0.82), p-value <0.05]. Furthermore, the number of children at home was a significant predictor of mothers’ immunization status as those with five children or more were ten times more to be protected against tetanus [OR= 10.54 (95% C.I 4.30-25.86), p-value <0.05]. We conclude that this low rate of TT vaccine uptake found in this study among pregnant women increases the number of newborn babies susceptible to contracting neonatal tetanus. This study provides useful information that can inform the will increase in the probabilities of morbidities and mortalities that result from maternal and neonatal tetanus. The findings of this study should be considered in development of communication strategies targeting and prioritizing at-risk groups to increase TT vaccine uptake among pregnant women in Sudan.

Vaccination is one of the most effective methods for preventing morbidity and mortality from COVID-19. Vaccine hesitancy has led to a decrease in vaccine uptake; driven by misinformation, fear, and perceptions of vaccine safety. Whole inactivated vaccines have been used in one-fifth of the vaccine recipients in Africa, however there is limited real-world data on their safety. We evaluated the reported side effects and factors associated with reported side effects following vaccination with whole inactivated COVID-19 vaccines - BBiBP-CorV (Sinopharm) and CoronaVac (Sinovac). A quantitative survey evaluating attitudes and side effects from vaccination was administered to 1016 adults presenting at vaccination centers. Two follow-up telephone interviews were conducted to determine side effects after the first and second vaccination dose. Overall, the vaccine was well tolerated; 26.0% and 14.4% reported side effects after the first and second dose respectively. The most frequent local and systemic side effects were pain at the injection site and headaches respectively. Most symptoms were mild, and no participants re-quired hospitalization. Participants who perceived COVID-19 vaccines as safe or had a personal COVID-19 experience were significantly less likely to report side effects. Our findings provide data on the safety and tolerability of whole inactivated COVID-19 vaccines in an African population, providing the necessary data to create effective strategies to increase vaccination and support vaccination campaigns.

COVID-19 pandemic disproportionately affected seven South Asian countries because of rampaging virus and weak health system response. Vaccination commenced in all countries during early 2021, once the vaccines became available in the international market. Vaccines were donated by international development partners, friendly countries and procured utilizing domestic resources and financial support from various agencies. All countries opted for a phasing of the vaccination by prioritizing high risk populations which included health care personnel, front line workers and elderly with comorbidities. Seven vaccines that had WHO emergency authorization usage were utilized in South Asia. India produced more than 2.4 billion doses of AstraZeneca vaccine and has indigenously developed five COVID-19 vaccines. Vaccine inequity was obvious and characterized by fewer people in South Asia vaccinated with single dose vis a vis the developed countries. Vaccine hesitancy was another obstacle that kept the vaccination rates low. Difficult to reach areas in Afghanistan, Bhutan, Maldives, Nepal could not fully access vaccines. South Asian countries need to strengthen their health system for efficient deployment of vaccines in future health emergencies. At the same time the global agencies and developed countries must address the issue of vaccine access to low-income countries to mitigate the impact of pandemic all over the world.

In this study, we surveyed over 600 participants to determine: a) major causes to mental stress during the pandemic and its future impacts, and b) diversity in public perception and acceptance (specifically for children) of Covid-19 vaccination. Statistical results and intelligent clustering outcomes indicate significant relationships between sociodemographic diversity, mental stress causes, vaccination perception, and Covid-19 infections. For instance, statistical results indicate significant dependence between mental stress due to Covid-19 and gender (p = 1.7e-05). Over 25% of males indicated work related stress comparing 35% in females however, females indicated more stressed (17%) due to relationships comparing to males (12%). Around 30% of Asian/Arabic participants don’t feel vaccination being safe as compared to 8% of white-British and 22% of white-European indicating significant dependence (p = 1.8e-08) with ethnicity. More specifically, vaccination acceptance for children is significantly dependent to ethnicity (p = 3.7e-05) where only 47% participants show willingness towards children’s vaccination. Primary dataset in this study along with experimental outcomes identifying sociodemographic information diversity with respect to public perception and acceptance of vaccination to children and potential stress factors might be useful for public and policy makers to be better prepared for future epidemics as well as working globally to combat mental health issues and running more effective vaccination campaigns.

Despite the availability of effective vaccines that lower mortality and morbidity associated with COVID-19, many countries including Italy adopted strict vaccination policies and mandates to increase the uptake of the COVID-19 vaccine. Such mandates have sparked debates on the freedom to choose whether or not to get vaccinated. In this study, we examined the people’s belief in vaccine choice as a predictor of willingness to get vaccinated among a sample of unvaccinated individuals in Italy. An online cross-sectional survey was conducted in Italy in May 2021. The survey collected data on respondents’ demographics and region of residence, socioeconomic factors, belief in the freedom to choose to be vaccinated or not, risk perception of contracting and transmitting the disease, previous vaccine refusal, opinion on adequacy of government measures to address the pandemic, experience in requesting and being denied government aid during the pandemic, and intent to accept COVID-19 vaccination. The analysis employed binary logistic regression models using a hierarchical model building approach to assess the association between intent to accept vaccination and belief in the freedom to choose to vaccinate, while adjusting for other variables of interest. 984 unvaccinated individuals were included in the study. Respondents who agreed that people should be free to decide whether or not to vaccinate with no restrictions on their personal life had 85% lower odds of vaccine acceptance (OR=0.15 ;95% CI,0.09,0.23) after adjusting for demographic and socioeconomic factors and their risk perception of contracting and transmitting COVID-19. Belief in the freedom to choose whether or not to accept vaccinations was a major predictor of COVID-19 vaccine acceptance among a sample of unvaccinated individuals in Italy in May 2021. This understanding of how individuals prioritize personal freedoms and the perceived benefits and risks of vaccines, when making health care decisions can inform the development of public health outreach, educational programs and messaging.

Parental refusal of childhood vaccines is a growing public health concern. Numerous reasons exist for this refusal, including religious, personal, and philosophical beliefs, and safety concerns. However, parental refusal of childhood vaccines is not simply an individualized problem for the family; this impacts herd immunity and affects the entire community. To improve vaccination rates among the pediatric population, understanding the thought process and decision-making behind parental opposition and refusal of vaccinations is essential. Using a survey developed to assess attitudes towards recommended childhood vaccines and the COVID-19 vaccine, this study examined the correlation between vaccine literacy and hesitancy among parents and legal guardians of elementary school-aged children in the Midwest. Responses were analyzed using Chi-squared tests on “R” software. Significant negative correlations were found between COVID-19 hesitancy and vaccine literacy, and resistance towards all vaccines and vaccine literacy. No significant negative correlations were found between hesitancy towards all vaccines and vaccine literacy, or hesitancy and literacy among different income and education brackets. Our results suggest that vaccine education may lessen vaccine hesitancy among parents and may be an essential factor in improving vaccination rates among the pediatric population.

On 11th March 2020, the World Health Organization declared COVID-19 as a pandemic. Vaccination programs have advanced greatly in the global health period, despite widespread anti-vaccination attitudes and misinformation. Vaccine hesitancy of COVID-19 vaccine is currently a major issue in Saudi Arabia. This cross-sectional study was carried out from June 25, 2021 to October 2021 in order to investigate the knowledge levels of acceptance and hesitancy of COVID-19 vaccine among Saudi’s nationals. The data was collected through a close-ended structured questionnaire from a total of 565 respondents. Overall, 78.41% respondents were female, 62.48% having university level education and 61.06% were unemployed. Majority of the participants 82.30% (n=465) think that Pfizer vaccine has the highest efficiency against COVID-19. Our study concludes that majority of the participants have satisfactory knowledge about COVID-19 vaccination. Concerns over vaccine components, effectiveness of vaccine and possible side effects are among the key causes for vaccine hesitancy.

Background: Human papillomavirus (HPV) is responsible for most cervical cancer cases globally, with women living with HIV at higher risk of persistent HPV infection and HPV-associated disease. The HPV vaccine is a promising solution to reducing cervical cancer rates, but its uptake among women living with HIV in Nigeria is unknown. Methods: A facility-based, cross-sectional survey was conducted with 1,371 women living with HIV to assess their knowledge of HPV, cervical cancer, and the HPV vaccine, as well as their willingness to pay for the vaccine at the HIV treatment clinic, Nigerian Institute of Medical Research, Lagos. Willingness to pay for the HPV vaccine was also assessed. Multivariable logistic regression models were developed to identify factors associated with willingness to pay for the HPV vaccine. Results: The study found that 79.1% of participants had not heard of the vaccine, and only 29.0% knew of its efficacy in preventing cervical cancer. Moreover, 68.3% of participants were unwilling to pay for the vaccine, and the average amount they were willing to pay was low. Knowledge of HPV, the HPV vaccine, cervical cancer, and income were factors associated with willingness to pay for the vaccine. Health workers were the primary source of information. Conclusion: The study found that 79.1% of participants had not heard of the vaccine, and only 29.0% knew of its efficacy in preventing cervical cancer. Moreover, 68.3% of participants were unwilling to pay for the vaccine, and the average amount they were willing to pay was low. Knowledge of HPV, the HPV vaccine, cervical cancer, and income were factors associated with willingness to pay for the vaccine. Health workers were the primary source of information.

Fighting against the COVID-19 pandemic caused by the SARS-CoV-2 virus is one of the most critical challenges facing the global health system today. The possibility to identify the group of persons in the cohort of people under 50 years old, who are sensitive to the COVID-disease by non-invasive methods, is a very perspective approach for estimating the epidemiological state of the human population. The study aimed to identify the features of people's faces with COVID-19 that the most correlate with disease severity could serve as one of these approaches. For this aim, 525 photos of patients' faces with different outcomes of COVID-19 disease were analyzed using the Dlib face recognition convolutional neural network pre-trained for face recognition. Face descriptor vectors were obtained using the convolutional neural network. Facial features were found that predict a person's sensitivity to the SARS-CoV-2 virus (disease severity), and the contribution of each of the features to the risk of developing a severe form of COVID in a person was found. The accuracy of the binary classification of the individual severity of the COVID-19 course using the k-nearest neighbors algorithm on the test dataset was accuracy - 84%, AUC - 0.90.

The effect of SARS-CoV-2 pandemic has been subsided significantly following the rapid development of vaccine. However, patients with cancer and immunosuppressed state, who are more prone to mortality and morbidity due to this infection, were excluded from majority of the vaccine trials. Moreover, suggested dose modification for cancer and immunosuppressed patients are often not followed because of lack of awareness or unavailability of vaccination schedule. This review will try to bridge this knowledge gap by summarizing the current suggestions of dose modification of COVID-19 vaccine for patients with cancer and immunosuppression.

Understanding vaccine hesitancy in organ transplant recipients (OTR) is critical, given clear, alt-hough attenuated, benefits from vaccination. Adult OTR were surveyed regarding vaccine-related values and a novel outcome variable called Vaccine Acceptance Composite Score (VACS) was built as the average Likert score of 7 domains of vaccination confidence. Of 46 OTR included (93.5% kidney transplant recipients), 32.6% were female, 13.3% Black, 6.77% Hispan-ic/Latino/a/x; median age was 58 years. Patients were most concerned about COVID-19 vac-cine-associated risks (46.3%), its potential effect on allograft (47.6%) and motives of government officials involved with vaccine policy (55.6%). Politically conservative patients were likely to have a significantly lower VACS, while those who lived with someone ≥65 had a higher VACS. The VACS was not significantly associated with race, income, religious beliefs, comorbidities, COVID-19 history, or influenza vaccination status. Higher VACS was significantly associated with ≥3 and ≥4 COVID-19 immunizations. This study highlighted political beliefs and elderly household members as correlates of vaccine acceptance among OTR. The VACS may be a useful tool to help standardize multifaceted analyses in vaccination-focused behavioral research, as well as identify individuals and groups at risk for vaccine hesitancy, who may benefit from tai-lored outreach and educational interventions.

Unprecedented in scale, immense COVID-19 immunization programmes have been rolled out globally. This article explores aspects of hypothetical vaccine acceptability in Soweto, South Africa, shortly before such vaccines became available. Whereas hypothetical acceptance was normative, this has not translated into uptake today, which remains concerningly low in South Africa, especially in Soweto. For that reason, we mobilise anthropological concepts to analyse acceptance, hesitancy, and denial, respectively, to gauge and understand public proclivity to inoculate. We find that COVID-19’s haphazard mediatization generated a ‘field of suspicion’ towards authorities and vaccination, which, amplified by dis- and misinformation, fostered othering, hesitancy, and denial considerably. It remains paramount during vaccination rollouts to unveil and address aspects detrimental to vaccine confidence and selectivity, especially in lower-income groups for underlying, context-specific cultural, spiritual, historical, and socioeconomic reasons. Appropriate mediazation alongside a debunking of counterfactual claims is crucial in driving forward immunization.

This tutorial is organized into three major sections—viruses, vaccines and the race for a Covid-19 vaccine. The goal is to provide enough background on viruses, history of vaccines, and the science of vaccinology founded on the principles of immunity. The hope is that this will enable us to understand the challenges, methods and prospects for developing a safe and effective vaccine against SARS-CoV-2. Many important viruses such as smallpox, HIV, HCV and SARS-CoV-2 which is responsible for causing the Coronavirus disease 2019 (Covid-19) are presented in detail, which is then followed by a description of different vaccine development methods and strategies. The tutorial then discusses different candidate SARS-CoV-2 vaccines and provides specific details of many of the prospective vaccines on the leader-board which are undergoing clinical trials. The tutorial concludes with a realistic projection for a safe and effective vaccine against SARS-CoV-2 based on the historical scientific record.

The COVID-19 pandemic continues to ravage the world, with the United States being highly affected. A vaccine provides the best hope for a permanent solution to controlling the pandemic. However, to be effective, a vaccine must be accepted and used by a large majority of the population. Structural equation modelling was used to analyze the relationships of several factors with attitudes toward potential COVID-19 vaccination. The survey was administered to 316 respondents across the United States by a survey corporation. Prior vaccine usage and attitudes predicted attitudes towards COVID-19 vaccination. Assessment of the severity of COVID-19 for the United States was also predictive. Approximately 68% of all respondents were supportive of being vaccinated for COVID-19, but side effects, efficacy, and length of testing remained concerns. Longer testing, increased efficacy and development in the United States were significantly associated with increased vaccine acceptance. Messages promoting COVID-19 vaccination should seek to alleviate the concerns of those who are already vaccine-hesitant. Messaging directed at the benefits of vaccination for the United States as a country would address the second predictive factor. Enough time should be taken to allay concerns about both short and long-term side effects before a vaccine is released.

Despite the crucial role the COVID-19 vaccine played in curbing the pandemic, a significant portion of Black and African American individuals expressed hesitancy in being vaccinated. This review aimed to identify the determinants of COVID-19 vaccine hesitancy among Black and African American individuals in the USA. The literature search was conducted in December 2022 according to the PRISMA criteria focusing on empirical studies. Data extraction methods, critical appraisal, and secondary thematic analysis were conducted on both quantitative and qualitative studies. Sixteen quantitative studies identified key factors associated with vaccine hesitancy such as confidence in vaccine effectiveness, safety, and trust in the healthcare system. 14 qualitative studies revealed major themes of mistrust, fear, and information needs, including historical mistrust, concerns about the vaccine development process, and contemporary institutional mistrust. The synthesis of quantitative and qualitative findings derived from this review provides a nuanced understanding of determinants of vaccine hesitancy in Black and African American communities in the USA, offering a foundation for the development of evidence-based interventions. Mistrust in the healthcare system, fear, and informational gaps on vaccine safety and effectiveness have been identified as significant barriers to vaccination, demanding targeted interventions.

The global COVID-19 pandemic has affected all spheres of human life, resulting in millions of deaths and overwhelming medical facilities. Moreover, the world has witnessed great financial hardship because of job losses resulting in economic havoc. Many sections of society have contributed in different ways to slow the spread of the virus and protect public health. For example, medical scientists are praised for their efforts to develop COVID-19 vaccines. Clinical trials have shown that the COVID-19 vaccines are highly effective in preventing symptomatic COVID-19 infections. However, many people around the world have been hesitant to get vaccinated. Vaccine misconceptions have emerged and increased due to a combination of factors, including the availability of information on the Internet and the influence of celebrities and opinion leaders. In this context, we have analyzed ChatGPT responses to relevant queries on vaccine misconceptions. The positive responses and supportive opinions provided by the AI chatbot could be instrumental in shaping people’s perceptions of vaccines and in encouraging users to get vaccinated and reduce misconceptions.

Background: Understanding the distribution of HPV types in cervical cancer cases is crucial for evaluating the effectiveness of HPV screening and vaccination in reducing cervical cancer burden. This study aimed to assess genotype prevalence among 178 cervical cancer cases detected during a 20-year screening period in Northern Norway and compare the potential efficacy of HPV vaccines in preventing cervical cancer. Methods: A total of 181 formalin-fixed paraffin-embedded (FFPE) tissue samples from women diagnosed with cervical cancer between 1995 and 2015 in Troms and Finnmark, Norway, were analyzed using a 45-type HPV DNA test. The results were compared to a 7-type HPV mRNA test targeting oncogenic types included in the nonavalent HPV vaccine. Results: Invalid HPV test results were observed in 1.7% (3/181) of the samples and were subsequently excluded from further analysis. Among the remaining cases, 92.7% (165/178) tested positive for HPV using any test combination. HPV DNA was detected in 159 cases (89.3%), while HPV mRNA was detected in 149 cases (83.7%). The most prevalent HPV types were 16 and 18, responsible for 70.8% of the cases, with the nonavalent vaccine types accounting for 86.6% of cases. HPV 35 was identified in eight cases (4.5%). Conclusion: The bivalent/quadrivalent HPV vaccines have the potential to prevent 76.4% (126/165) of HPV-positive cervical cancer cases, while the nonavalent vaccine could prevent 93.3% (154/165) of cases. Tailoring screening strategies to target HPV types with the highest oncogenic potential may improve cervical cancer detection and enable targeted interventions for high-risk individuals. The use of a 7-type HPV mRNA test holds promises as an advantageous approach.

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.

This study focuses on cardiovascular effects, particularly myocarditis and pericarditis events, after BNT162b2 mRNA COVID-19 vaccine injection in Thai adolescents. This prospective cohort study enrolled students from two schools aged 13–18 years who received the second dose of the BNT162b2 mRNA COVID-19 vaccine. Data including demographics, symptoms, vital signs, ECG, echocardiography and cardiac enzymes were collected at baseline, Day 3, Day 7, and Day 14 (optional) using case record forms.We enrolled 314 participants; of these, 13 participants were lost to follow up, leaving 301 participants for analysis. The most common cardiovascular effects were tachycardia (7.64%), shortness of breath (6.64%), palpitation (4.32%), chest pain (4.32%), and hypertension (3.99%). Seven participants (2.33%) exhibited at least one elevated cardiac biomarker or positive lab assessments. Cardiovascular effects were found in 29.24% of patients, ranging from tachycardia, palpitation, and myopericarditis. Myopericarditis was confirmed in one patient after vaccination. Two patients had suspected pericarditis and four patients had suspected subclinical myocarditis. Conclusion: Cardiovascular effects in adolescents after BNT162b2 mRNA COVID-19 vaccination included tachycardia, palpitation, and myocarditis. The clinical presentation of myopericarditis after vaccination was usually mild, with all cases fully recovering within 14 days. Hence, adolescents receiving mRNA vaccines should be monitored for side effects. Clinical Trial Registration: NCT05288231

Despite the research conducted worldwide, there is no treatment specific for SARS-CoV-2 infection with efficacy proven by randomized controlled trials. A chance for a breakthrough is vaccinating the majority of the global population. The public opinion surveys on vaccine hesitancy prompted our team to investigate the Polish medical community's attitude towards the SARS-CoV-2 and influenza vaccinations. In-person and online surveys of Healthcare Workers (HCWs): doctors, nurses, medical students, and other allied health professionals (n=419) took place between 14.09.2020 and 5.11.2020. In our study, 68.7% of respondents would like to be vaccinated with the COVID-19 vaccine. The safety and efficacy of vaccination against COVID-19 would persuade 86.3% of hesitant and those who would refuse to be vaccinated. 3.1% of all respondents claimed that no argument would convince them to get vaccinated. 61.6% of respondents declared a willingness to receive an influenza vaccination, of which 83.3% were also inclined to receive the planned COVID-19 vaccination. Although a significant part of respondents - 62.5% (262/419) indicated, they trusted the influenza vaccine more than the COVID-19 vaccine in direct comparison, more respondents intended to get the COVID-19 vaccination than the influenza vaccine in the 2020/2021 season.

In response to the COVID-19 crisis, decisionmakers in countries around the world adopted policies such as lockdowns, mask requirements, and once vaccines became available, vaccine mandates and vaccine passports. However, political polarization and differences in risk perceptions in the populous generated strong support for and opposition to such measures. This research identifies the factors with support for and against vaccine mandates and vaccine passports. An online survey of COVID-19 health experiences in the United States population was conducted. The survey collected information regarding potential reasons for why respondents might favor or oppose COVID-19 vaccine mandates and vaccine passports, including experiences with COVID-19 illness and COVID-19 vaccinations by respondents and those in their social circles. Analysis using a Logit regression technique was conducted to identify factors influencing the likelihood of opposing vaccine mandates and vaccine passports. The survey was completed by 2,840 participants between December 18 and 23, 2021. Respondents who knew someone who experienced a health problem following vaccination were more likely to oppose vaccine mandates (OR: 2.040, 95% CI: 1.635-2.254, and vaccine passports (OR: 1.691, 95% CI: 1.361-12.101)) Twenty-two percent (612 of 2,840) of respondents reported that they knew at least one person who had experienced a health problem following COVID-19 inoculation. Perceptions of vaccine safety based on personal experiences appear to be an important determinant of opposition to vaccine mandates and vaccine passports.

Vaccine hesitancy substantially impacts global vaccination rates. During the COVID-19 pandem-ic in Germany, vaccination uptake exhibited considerable regional disparities. To assess the fac-tors contributing to this variation, we examined the influence of sociodemographic variables on COVID-19, COVID-19 booster, and influenza vaccinations within a cohort of 37,078 participants from 13 German federal states in the digital health cohort study, DigiHero. Our findings re-vealed variations in vaccination rates based on sociodemographic factors. However, these fac-tors had limited explanatory power regarding regional differences in vaccine uptake. In contrast, we found substantial correlations between regional support of specific parties during last local elections and the vaccination uptake at Landkreis-level. In conclusion, sociodemographic factors alone did not suffice to explain the regional disparities in vaccine uptake. Political stances can play a major role, but the current investigation did not assess the individual political orienta-tion, but used only ecological approach.

Hispanic/Latino communities have suffered a disproportionate burden due to the COVID-19 pandemic. Although Puerto Rico has one of the highest COVID-19 primary series vaccination rates nationwide, this estimate contrasts with the low uptake of booster doses (32.7%). This study aimed to assess health belief correlates of COVID-19 vaccine booster uptake. PR-CEAL recruited 787 participants via an online survey between December 2021 and January 2022. Sociodemographic characteristics and questions framed using the Health Belief Model were assessed. Analyses included adjusted Poisson regression models to estimate prevalence ratios (PR) of booster refusal. Overall, 22% of participants planned (10%) or refused (12%) the vaccine booster. Participants with lower income [PR=1.92; 95%CI=1.30, 2.84], in disagreement with vaccine benefits [PR=4.16; 95%CI=3.06, 5.64], and in agreement with booster concerns [PR=2.93; 95%CI=2.12, 4.04], efficacy [PR=2.76; 95%CI=2.00, 3.82], and safety [PR=2.97; 95%CI=2.15, 4.08] were significantly more likely to refuse the booster. Booster vaccination refusal was associated with lower perceived vaccine benefits and higher barriers among adults in Puerto Rico. Results informed CEAL team intervention strategies for public health campaigns to increase booster vaccine uptake.

We aimed to assess awareness, knowledge, and attitudes of healthy pregnant women towards human papillomavirus (HPV), to estimate factors associated with a positive attitude towards HPV immunization and to assess the uptake of the vaccine among their children. A cross-sectional study was conducted at the University Clinic of Gynecology and Obstetrics, Belgrade, Serbia among pregnant women attending their regular gynecological check-ups at the 12th gestational week. Knowledge about HPV and HPV vaccine was assessed using a specifically designed 12-item and 5-item questionnaires. Out of total 265 included women, 79.3% had heard of HPV, and 37.5% knew that HPV vaccine exists. HPV vaccine knowledge score was associated with higher odds for a positive attitude towards vaccination of both female (OR = 4.10, 95% CI 1.50-11.29) and male (OR = 3.71, 95% CI 1.52-9.01) child. The number of children (OR = 1.32, 95% CI 1.04-1.67) and high vaccine knowledge score (OR = 1.64 95% CI 1.13-2.39) were independent predictors associated with willingness to vaccinate child against HPV. The gynecologist was the preferable point of reference for information seeking about the HPV vaccine. Despite relatively high HPV awareness and knowledge among pregnant women in Serbia, about one-third of them are HPV vaccine aware, and are willing to vaccinate their children against HPV.

Utility of vaccine campaigns to control coronavirus disease 2019 (COVID-19) is not merely dependent on vaccine efficacy and safety. Vaccine acceptance among the general public and the healthcare workers, appears to have a decisive role for successful control of the pandemic. The aim of this review was to provide an up-to-date assessment of COVID-19 vaccination acceptance rates worldwide. A systematic search of the peer-reviewed English survey literature indexed in PubMed was done on December 25, 2020. Results from 30 studies, met the inclusion criteria and formed the basis for final COVID-19 vaccine acceptance estimates. Results of an additional recent survey from Jordan and Kuwait was considered in this review as well. Survey studies on COVID-19 vaccine acceptance rates were found from 33 different countries. Among adults representing the general public, the highest COVID-19 vaccine acceptance rates were found in Ecuador (97.0%), Malaysia (94.3%), Indonesia (93.3%) and China (91.3%). On the other hand, the lowest COVID-19 vaccine acceptance rates were found in Kuwait (23.6%), Jordan (28.4%), Italy (53.7), Russia (54.9%), Poland (56.3%), US (56.9%), and France (58.9%). Only eight surveys among healthcare workers (doctors, nurses) were found, with vaccine acceptance rates ranging from 27.7% in the Democratic Republic of the Congo to 78.1% in Israel. In a majority of survey studies among the general public (62%), the acceptance of COVID-19 vaccination showed a level of ≥ 70%. Low rates of COVID-19 vaccine acceptance were reported in the Middle East, Russia, Africa and several European countries. This could represent a major problem in the global efforts that aim to control the current COVID-19 pandemic. More studies are recommended to address the scope of COVID-19 vaccine hesitancy. Such studies are particularly needed in the Middle East Africa, Eastern Europe, Central Asia, Middle and Latin America.

This study aimed to evaluate the mixed and homogeneous application of the inactivated SARS-CoV-2 vaccine CoronaVac (CV) and the mRNA vaccine BNT162b2 (BNT). This prospective cohort study included 235 health care workers, who had received two prime shots with CoronaVac. They were divided into three cohorts after the third month: Cohort-I (CV/CV); Cohort-II (CV/CV/CV) and Cohort-III (CV/CV/BNT). Anti-S-RBD-IgG and total an-ti-spike/anti-nucleocapsid-IgG antibody concentrations were examined in vaccinated health workers at the 1st, 3rd and 6th months following the second dose of the vaccination. The mean age of 235 health care workers who participated in the project was 39.51±10.39 (min-max: 22-64). At the end of the 6th month, no antibodies were detected in 16.7% of Cohort-I participants, and anti-S-RDB IgG levels showed a decrease of 60% compared to the levels of the 3rd month. The antibody concentrations of the 6th month were found to have increased by an average of 5.13 times compared to the 3rd-month levels in the Cohort-II and 20.4 times in Cohort-III. The heterologous vaccination strategy “CoronaVac and BNT162b2 regimen” is able to induce a stronger immunity and it will help remove inequalities in the developing world where CoronaVac was the initial prime.

Objective: On March 11, 2020 the WHO declared that COVID-19 is pandemic. Among the risk factors for many infectious diseases, a role of the ABO blood group system is reported in the literature. We argue whether it is necessary to investigate the relationship between ABO blood groups and susceptibility to SARS-CoV-2 infection and if we should consider some blood groups as potential risk factors for COVID-19. Results: Based on the scientific evidence reported in this letter, we believe that further studies are needed to investigate how the ABO polymorphism influences the host susceptibility, individual response and clinical risk for SARS-CoV-2 infection.

: Background: Vaccination against COVID-19 has been the main strategy used by most countries to limit the spread of the virus. However, vaccine uptake has been low in Africa, leading to the implementation of several interventions in order to improve vaccine coverage. This study was conducted due to the lack of information about COVID-19 vaccine coverage and the factors associated with vaccine hesitancy. Methods: This cross-sectional study was carried out in Kinshasa city using multi-stage random sampling. A total of 2160 households were included in the study. The data were analyzed using Stata 15 software. The means and standard deviations were calculated for normally distributed continuous variables, while proportions with their 95% confidence intervals (CIs) were calculated for categorical variables. Pearson’s chi-square test or Fisher’s exact test was used to test the associations between dependent variables and each independent variable. Logistic regression was used to identify the factors associated with hesitancy receiving the COVID-19 vaccination. Results: The majority of respondents were aged between 25 and 34 and 35 and 49 (28.9%). During this study, 15% (95% CI [13.25–17.9]) of respondents had received at least one dose of the COVID-19 vaccine. Among the reasons given for refusing to be vaccinated, most respondents cited concerns about the vaccine being unsafe or causing adverse reactions (45%). Among the reasons given for accepting the vaccine, 26% thought that the vaccine prevented superinfection. The factors associated with hesitancy toward the COVID-19 vaccine were female gender, an age of less than 35 years, and living in non-slum households. Conclusions: Despite the interventions implemented across the country, the reluctance to be vaccinated remains a problem; this could lead to poor health outcomes, especially among the elderly and those with pre-existing conditions. It is important to step up awareness-raising campaigns in the community in order to increase the uptake of vaccination.

In the recent days, lipid nanoparticles have been successfully emerged as one of the most advanced technology for highly efficient in vivo delivery of exogenous mRNA, especially for delivery of COVID-19 vaccines. For the vaccines to be successful or protective, they require highly efficient mRNA delivery systems. However, developing effective, translatable vaccines with better safety against some of the SARS‐CoV‐2 variants is still a challenge. Lipid nanoparticles (LNPs) are composed of four different types of lipids including ionizable lipids, helper or neutral lipids, cholesterol and polyethylene glycol (PEG) attached lipids. In this review, we present recent advancements and insights in designing the advanced LNPs and their composition and properties, with a subsequent discussion on the development of COVID-19 vaccines. In particular, as the ionizable lipids are most important drivers for complexing the mRNA and in vivo delivery, the role of ionizable lipids in mRNA vaccines discussed in detail. Furthermore, the use of LNPs as effective delivery vehicles for vaccination, genome editing, and protein replacement therapy were discussed. Finally, expert opinion of LNPs for mRNA vaccines were discussed which might address the future challenges in the development of mRNA vaccines employing highly efficient LNPs using novel set of ionizable lipids.

Uncovering the predictors of vaccine immunogenicity is essential for infection control. We have reported that the most prevalent polymorphism of the aldehyde dehydrogenase 2 (ALDH2) gene, rs671, may be associated with an attenuated immune system. To test the inverse relation between rs671 and antibody production after COVID-19 vaccination, the levels of anti-SARS-CoV-2 Spike protein S1 subunit (S1) IgG were repeatedly measured for four months before and after vaccination with BNT162b2 or mRNA-1273, in 88 Japanese workers and students (including 45 females, aged 21–56 years, with an rs671 variant allele frequency of 0.3). The mixed model including fixed effects of the vaccine type, weeks post vaccination (categorical variable), sex, age, body height, smoking status, ethanol intake, exercise habit, perceived stress, steroid use, allergic diseases, and dyslipidemia, indicated an inverse association between log-transformed anti-S1 IgG levels and the number of rs671 variant alleles (partial regression coefficient = -0.15, p = 0.002). Our study indicated for the first time that the variant allele of ALDH2, rs671, is associated with the attenuated immunogenicity of COVID-19 mRNA vaccines. Our finding may provide a basis for personalized disease prevention based on a genetic polymorphism that is prevalent among East Asians.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has provoked major stresses on the health care systems of several countries, and caused the death of more than a quarter of a million people globally, mainly in the elderly population with pre-existing pathologies. Previous studies with coronavirus (SARS-CoV) point to gender differences in infection and disease progression with increased susceptibility in male patients, indicating that estrogens may be associated with physiological protection against the coronavirus. Therefore, the objectives of this work are threefold. First, we aim to summarize the SARS-CoV-2 infection pathway and the roles both the virus and patient play in COVID-19 (Coronavirus disease 2019) progression, clinical symptomology, and mortality. Second, we detail the effect estrogen has on viral infection and host infection response, including its role in both the regulation of key viral receptor expression and the mediation of inflammatory activity. Finally, we describe how ERs (estrogen receptors) and RAGE (receptor for advanced glycation end-products) play a critical role in metabolic pathways, which we envisage could maintain a close interplay with SARS-CoV and COVID-19 mortality rates, despite a current lack of research directly determining how. Taken together, we present the current state of the field regarding SARS-CoV-2 research and illuminate where research is needed to better define the role both estrogen and metabolic comorbidities have in the COVID-19 disease state, which can be key in screening potential therapeutic options as the search for effective treatments continue.

In the wake of the Covid-19 crisis, a need has arisen to prevent and treat two related conditions, Covid vaccine injury and long Covid, both of which have a significant vascular component. Therefore, the management of these conditions require the development of strategies to prevent or dissolve blood clots and restore circulatory health. This review summarizes the evidence on strategies that can be applied to treat both long and vaccine injuries based on similar mechanisms of action.

An important step towards COVID-19 pandemic control is adequate knowledge and adherence to mitigation measures, including vaccination. We assessed the level of COVID-19 knowledge, attitudes, and practices among residents from an urban informal settlement in the City of Nairobi (Kibera), and a rural community in western Kenya (Asembo). A cross-sectional survey was implemented from April to May 2021 among randomly selected adult residents from a population-based infectious diseases surveillance (PBIDS) cohort in Nairobi and Siaya Counties. Factors associated with the level of COVID-19 KAP, were assessed using multivariable regression methods. COVID-19 vaccine acceptance was 83.6% for the participants from Asembo and 59.8% in Kibera. The reasons cited for vaccine hesitancy in Kibera were safety concerns (34.0%), insufficient information available to decide (18.0%), and a lack of belief in the vaccine (21.0%), while the reasons in Asembo were safety concerns (55.0%), insufficient information to decide (26.0%) and lack of belief in the vaccine (11%). Our study findings suggest the need for continued public education to enhance COVID-19 knowledge, attitudes, and practices to ensure adherence to mitigation measures. Urban informal settlements require targeted messaging to improve vaccine awareness, acceptability, and uptake.

Background: COVID-19 booster uptake remained poor among healthcare workers (HCW) despite evidence of improved immunity against Delta and Omicron variants. While most studies used a questionnaire to assess hesitancy, this study aimed to identify factors affecting true booster hesitancy by examining actual vaccine uptake across time. Method: COVID-19 vaccination database records among HCW working at 7 Singaporean public primary care clinics between January to December 2021 were extracted, with gender, profession, place of practice, vaccination type and dates. Time to booster was calculated from the date of vaccination minus date of eligibility. Chi-square test was used to compare relationship between 1st dose and booster hesitancy, Kaplan-Meier method and Log-rank test were adopted to evaluate differences in cumulative booster uptake. Multivariate cox regression was used to investigate predictors for timely booster vaccination. Vaccination rate was charted across time and corroborated with media releases pertaining to legislative changes. Results: 877 of 891 (98.9%) primary care HCW were fully vaccinated, 73.8% of eligible HCW had taken the booster. HCW were less booster hesitant [median 16 (5-31.3) days] compared to the 1st dose [median 39 (13-119.3) days]. 1st dose hesitant HCW were more likely to be booster hesitant (OR=3.66, 95%CI 2.61-5.14). Adjusting for sex, workplace and time to 1st dose, ancillary (HR=1.53, 95%CI 1.03-2.28), medical (HR=1.8, 95%CI 1.18-2.74) and nursing (HR=1.8, 95%CI 1.18-2.37) received boosters earlier compared with administrative staff. No temporal relationship was observed between booster uptake, legislative changes and COVID-19 infection numbers. Conclusion: Vaccine hesitancy among HCW had improved from booster to 1st dose, with timely booster vaccination among medical and nursing staff. Tailored education, risk messaging and strategic legislation might help to reduce delayed booster vaccination.

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease that was first reported in Wuhan, China and has subsequently spread worldwide. In the absence of any antiviral or immunomodulatory therapies, the disease is spreading at an alarming rate. 5 to 10% of recovered patients in Wuhan test positive again; this suggest that for controlling COVID-19, vaccines may be better option than drugs. A clinical trial to evaluate an anti-COVID-19 vaccine has started recently. However, its efficacy and potency have to be evaluated and validated. As an alternative, we are presenting a first-of-its-kind, designed multi-peptide subunit based epitope vaccine against COVID-19. The vaccine construct comprise an adjuvant, CTL, HTL, and B-cell epitopes joined by linkers. The vaccine is non-toxic, non-allergenic, thermostable and immunogenic with the capability to elicit a humoral and cell-mediated immune response. The findings are validated with high-end computation-based methods. This unique vaccine is made up of 33 highly antigenic epitopes from three proteins that have a prominent role in host receptor recognition, viral entry, and pathogenicity. We advocate this vaccine must be synthesized and tested urgently as public health priority.

This prospective study provides data on long-term humoral immunogenicity of a heterologous off-label vaccine regimen combining the adenoviral vectored ChAdOx1 nCoV-19 from Astra-Zeneca (ChAd) with the mRNA-1273 vaccine from Moderna (m1273) in comparison to two different homologous mRNA vaccine schedules. Of the 316 COVID-19 naïve adult health care workers (HCW) included to complete a survey on vaccine-associated symptoms (VAS), 197 had received the homologous BNT162b2 mRNA vaccine from Pfizer/BioNTech (BNT/BNT), 76 the homologous m1273/m1273, and 43 the heterologous ChAd/m1273 vaccine regimen. Concentration of antibodies against SARS-CoV-2 spike protein in plasma 5-7 months after the second vaccine dose was higher in the m1273/m1273 and ChAd/m1273 than the BNT/BNT vaccine group. The frequency of systemic VAS after first vaccine dose was 86% after ChAd compared to 35% and 39% after BNT and m1273, respectively (p &lt; 0.0001), and after second vaccine dose highest (89%) in the m1273/m1273 group (p &lt; 0.001). Individuals with systemic VAS achieved higher levels of antibodies irrespective of vaccine regimen. In conclusion, VAS serve as a strong predictor of long-term humoral immune response, and the heterologous ChAd/m1273 vaccine regimen provides an at least equal long-term humoral immune response compared with the standard vaccine regimens used in Denmark.

There is a lack of information on vaccination for pregnant women in the Brazilian literature. Our aim was to evaluate the data on vaccines recorded on the pregnancy card and knowledge about the importance of vaccination for women admitted for labor in a reference public tertiary maternity unit in Presidente Prudente, São Paulo, Brazil. Vaccine data as prescribed by the National Immunization Program of Brazil (NIP) in prenatal cards for patients in labor from the 45 municipalities of the western region of São Paulo state were obtained. A questionnaire relating to knowledge about the types and importance of vaccination in pregnancy was applied. All vaccines indicated by the NIP were registered in only 12.0% of the prenatal cards, and 33.0% of cards registered any vaccines. In this group, 16.6% were aged between 14 and 21 years, and tetanus and COVID-19 were the most prevalent vaccines that they had heard of during prenatal care. Data on vaccines was poorly recorded in the cards, suggesting a lack of attention and unpreparedness of professionals working in primary care. Our study has countrywide and global relevance, and may be applied mainly in Latin American countries facing similar difficulties and limitations with low rates of vaccination during pregnancy.

AI-based approaches are increasingly being used to revolutionize vaccine development for COVID-19. Small molecules, peptides, and epitopes are being collected for therapy discovery, which could also direct AI-based models, screening, or generation [1]. AI-based models are being used for drug discovery and vaccine development, and pre-existing data is being leveraged through machine learning approaches for COVID-19 drug discovery and vaccine development [1]. The best candidate targets for future treatment development are being identified and evaluated using AI-based models [1]. AI-based approaches can be used to overcome challenges in manufacturing, storage, logistics, and safety and efficacy issues related to different vaccine candidates for COVID-19 [2]. AI algorithms can help identify the best vaccine candidates for COVID-19 while considering the efficiency of antigenic peptides for immune response generation [2]. The presentation of antigenic peptides by major histocompatibility complex (MHC) class II molecules is the first step after COVID-19 vaccine administration for any vaccine-induced immune response [2]. Thus, AI-based models are being used to identify the best vaccine candidates for COVID-19 and to ensure that the vaccine-induced immune response is efficient and safe. The utilization of AI-based methods to address logistical, manufacturing, storage, safety, and efficacy issues regarding several COVID-19 vaccine candidates will be examined in this study. Additionally, while considering the effectiveness of antigenic peptides for the induction of an immune response, we will determine the best potential targets for the next treatment development and assess how AI-based models can help discover the best vaccine candidates for COVID-19. This research ultimately intends to offer insights into how AI-based techniques can transform COVID-19 vaccine development and how they can be applied to address vaccine development issues. In this paper, we focus on recent advances in using artificial intelligence to develop COVID-19 drugs and vaccines, as well as the potential of intelligent training in discovering COVID-19 therapeutics, highlighting potential challenges and solutions.

The coronavirus disease (COVID-19) is a respiratory tract infection caused by the new virus SARS-CoV-2. In March 2020, the World Health Organization (WHO) declared a worldwide COVID-19 pandemic. Since then, there has been a rush to find preventative or curative treatment. This arrived with the appearance of the COVID-19 vaccine, months after the declaration of the pandemic. In the setting of global COVID-19 immunization, there have been reports of rare skin immune-mediated diseases (IMD) after COVID-19 vaccination, particularly systemic sclerosis. Systemic sclerosis (SSc) is the most reported new onset IMD following messenger RNA (mRNA) COVID-19 vaccination. The pathogenesis of SSc is not fully understood, and the diagnosis is based on clinical symptoms. We report a 54-year-old male, with no prior history of autoimmune disorder, with rapid and progressive skin thickening (Modified Rodnan skin score 30/51), weeks after his mRNA COVID-19 vaccination. Antinuclear antibodies (ANA) showed a strongly positive nuclear fine-speckled pattern, but no SSc autoantibodies were found. The patient was diagnosed with SSc based on the persistence of autoantibodies and the clinical criteria according to the 2013 American College of Rheumatology/European League Against Rheumatism classification. Due to the proximity of the two events, we hypothesized a cross-reaction between COVID-19 vaccination and, in genetically predisposed patients, an emergence of systemic sclerosis. Our case suggests a potential relationship between the mRNA COVID-19 vaccine and new-onset autoimmune diseases. Physicians should be aware of this possible association.

Introduction: Real-world safety studies can provide important evidence on the thromboembolic risk associated with COVID-19 vaccines, considering that millions of people have been already vaccinated against COVID-19. In this study, we aimed to estimate the incidence of thromboembolic events after COVID-19 vaccination and to compare the Oxford–AstraZeneca vaccine with other COVID-19 vaccines. Methods: We conducted a retrospective real-world safety study using data from two different data sources: the Italian Pharmacovigilance database (Rete Nazionale di Farmacovigilanza, RNF) and the Campania Region Health system (Sistema INFOrmativo saNità CampanIA, SINFONIA). From the start date of the COVID-19 vaccination campaign (December 27th, 2021) to September 27th, 2022, information on COVID-19 vaccinations and thromboembolic evets were extracted from the two databases. The reporting rate (RR) and its 95% confidence interval (95%CI) of thromboembolic events for 10,000 doses was calculated for each COVID-19 vaccine. Moreover, the odds of being vaccinated with the Oxford–AstraZeneca vaccine vs. the other COVID-19 vaccines in cases with thromboembolic events vs. controls without thromboembolic events were computed. Results: A total of 12,692,852 vaccine doses were administered in Campania Region, of which 6,509,475 (51.28%) were in female and mostly related to the Pfizer-BioNtech vaccine (65.05%), followed by Moderna (24.31%), Oxford–AstraZeneca (9.71%), Janssen (0.91%), and Novavax (0.02%) vaccines. A total of 641 ICSRs with a COVID-19 vaccines and a vascular events were retrieved from the RNF for the Campania Region, of which 453 (70.67%) were in female. Most ICSRs reported the Pfizer-BioNtech vaccine (65.05%), followed by Oxford–AstraZeneca (9.71%), Moderna (24.31%), and Janssen (0.91%). A total of 2,451 events were reported in the ICSRs (3.8 events for ICSRs) of which 292 were thromboembolic events. The highe RRs of thromboembolic events were found with the Oxford–AstraZeneca vaccine (RR: 4.62, 95%CI: 3.50-5.99) and Janssen vaccine (RR: 3.45, 95%CI: 0.94-8.82). Thromboembolic events were associated with a higher likelihood of exposure to the Oxford–AstraZeneca vaccine compared to Pfizer-BioNtech (OR: 6.06; 95%CI: 4.22-8.68) and Moderna vaccines (OR: 6.46; 95%CI: 4.00-10.80). Conclusion: We observed a higher reporting of thromboembolic events with viral-vector based vaccines (Oxford–AstraZeneca and Janssen) and an increased likelihood of being exposed to the Oxford–AstraZeneca vaccine compared to the mRNA vaccines (Pfizer-BioNtech and Moderna) among thromboembolic cases.

In this article, ‎we examine an allocation issue faced by European Health Union (EHU)‎. ‎Given this situation, ‎we introduce the issue of vaccine selection. ‎The model proposed in this paper helps to implement vaccination optimally using matching theory. ‎By adopting the mechanism presented in this article, ‎this is done more easily and more quickly, ‎so that mortality in society is lower and public satisfaction is increased. ‎This is similar to the issues analyzed in the literature on the design mechanism of non-perishable goods.

Data on immunogenicity, immune response persistency, and safety of COVID-19 boosters in patients with comorbidities are limited. Therefore, we aimed to evaluate and compare three different boosters in individuals who received two doses of the BBIBP-CorV vaccine including underlying diseases and healthy cases as control. One hundred forty subjects including 63 ones with at least one of three underlying diseases (UD) (including obesity, hypertension, and diabetes mellitus) and 77 healthy ones (HC) who had received a booster dose (either PastoCovac Plus or PastoCovac or BBIBP-CorV) were enrolled. The presence of SARS-CoV-2 antibodies was assessed before the booster injection and 28, 60, 90, and 180 days after it. Moreover, the adverse events (AEs) were recorded on days 7 and 21 post-booster shot for evaluating safety outcomes. Significantly increased titers of anti-spike, anti-RBD, and neutralizing antibodies were observed in both UD and HC groups 28 days after the booster dose, although the titer rise of anti-spike IgG and anti-RBD IgG was insignificantly inferior in the UD group compared to the HC group. All antibodies’ titers declined, with no significant differences between the two groups over time. Notably, all specific antibodies persisted up to 180 days; particularly the neutralizing antibody in both groups. Furthermore, no significant difference in antibody levels was observed between each UD subgroup and the HC group, except for neutralizing antibodies in the hypertension sub-group. PastoCovac Plus and PastoCovac boosters induced higher antibodies’ fold rise in UD individuals than BBIBP-CorV booster recipients. Safety outcomes did not show any serious AEs after the booster injection. The overall incidence of AEs post the booster injection was higher in the UD group than the HC group. Furthermore, the highest systemic AEs rate was reported in the UD group receiving the BBIBP-CorV booster. In conclusion, administration of COVID-19 boosters can equally induce robust and persistent humoral immune responses in individuals with or without UD primarily vaccinated with 2-doses of the BBIBP-CorV. Protein-based boosters with higher antibodies' fold rise and lower AEs in individuals with comorbidities might be considered a better choice for these individuals.

COVID-19 infection in the pediatric population usually leads to a mild illness, however, a rare but serious complication of MIS-C has been seen in children. MIS-C usually presents 2-4 weeks after COVID-19 infection or exposure, and rare reports have been documented in neonates. Vaccinations for COVID-19 have been approved for children 6 months and above in the United States, and recent reports suggest significantly low prevalence and risk of complications of MIS-C in vaccinated children compared to unvaccinated children. Vaccinations for COVID-19 are safe and recommended during pregnancy and prevent severe maternal morbidity and adverse birth outcomes. Evidence from other vaccine-preventable diseases suggests that through passive transplacental antibody transfer, maternal vaccinations are protective against infections in infants during the first 6 months of life. Various studies have demonstrated that maternal COVID-19 vaccination is associated with the presence of anti-spike protein antibodies in infants, persisting even at 6 months of age. Further, completion of a 2-dose primary mRNA COVID-19 vaccination series during pregnancy is associated with reduced risk for COVID-19–associated hospitalization among infants aged 6 months or less. Therefore, it can be hypothesized that maternal COVID-19 vaccination can reduce the risk of and severity of MIS-C in infants. In this article, we review the literature to support this hypothesis.

Severe Acute Respiratory Syndrome Coronavirus 2 commonly known as SARS-CoV-2 is the utmost challenging pandemic that attracted scientific community to discover therapeutics as well as vaccination solutions to control SARS-CoV-2. Different diagnostic and detection methods have been improved and re-introduced from the previous observations of SERS and MERS. Due to the high mortality rate and fast spread, researchers all around the globe gathered to develop an effective vaccine. The review article summarizes various types of vaccines, mutants of virus, strategies in tackling virus, vaccine development and its global distribution with the focus on the use of mix and match of vaccines to fight the virus. The reported studies depict the design and production of successful COVID-19 vaccines with good efficacy as the selected vaccine population embrace high-risk personages i.e. above the age of 60, frontline workers and other essential service workers. We have targeted at delivering an outline of the determinations devoted to an effectual vaccine for novel Covid-19 that has restricted the domain by means of human health, economy, as well as life.

Rapid online surveys are an important tool in tracking the public’s knowledge and perceptions during infectious disease outbreaks. In June 2020, during the early phases of COVID-19 vaccines development, a survey had been conducted, aimed at assessing attitudes and opinions about vaccination of 885 Italian adults, in addition to their vaccine literacy levels (i.e. skills of finding, understanding and using information about vaccines). In January 2021, the same questionnaire has been administered to a similar population (n=160). Interactive vaccine literacy was significantly higher than in June 2020 (mean score 3.38 vs 3.27 respectively, P=.0021). The percentage of participants willing to be vaccinated against COVID-19 was assessed by the means of either-or questions, and was equally high in both surveys (>90%), which is quite reassuring, despite metrics based on categorical scales cannot identify hesitant subjects.

Introduction The COVID-19 virus was initially reported in Dec 2019 as the causative agent of a pneumonia breakout in Wuhan China. This virus rapidly spread from China to Europe and the East Coast of the United States eventually reaching the South West United States and indigenous tribes in mid -March. Since, then the indigenous tribes have been devasted by the virus which the Governor of New Mexico has likened as an existential threat. Methodology A PubMed search was performed utilizing the words: Navajo Indian, Indigenous Indian, Wuhan Virus, COVID-19, SARs coronavirus, ACE2, S protein, virulence, clinical presentation, epidemiology, genome, treatment, structure, MERs, pathogenesis and/or pathology alone and in combination with other terms. Each paper was evaluated by three content experts for quality, reproducibility, credibility and reputation of the journal Results: Navajo’s and other indigenous peoples may have elevated levels of ACE2 receptors in their lungs and other tissues allowing greater susceptibility to the COVID-19 virus. Increased levels of diabetes and protein nutrition are directly related to increased morbidity and mortality in this group while obesity, COPD, and heart diseas are not. The increased morbidity and mortality is exasperated by an inability to test for COVID-19 Conclusion: The infectivity rate of Navaho’s on the reservation is 22 times higher than the national average with a death rate near 4%. Comorbidites account for some of the increased morbidity and mortality while lack of access to adequate health care unnecessarily magnifies the poor outcome. The threat to indigenous tribes in the Southwest of COVID-19 is dire.

Various studies indicate that vaccination, especially with pneumococcal vaccines, protects against symptomatic cases of SARS-CoV-2 infection and death. This paper explores the possibility that pneumococcal vaccines in particular, but perhaps other vaccines as well, contain antigens that might be cross-reactive with SARS-CoV-2 antigens. Comparison of the glycosylation structures of SARS-CoV-2 with the polysaccharide structures of pneumococcal vaccines yielded no obvious similarities. However, while pneumococcal vaccines are primarily composed of capsular polysaccharides, some are conjugated to CRM197, a modified diphtheria toxin, and all contain about three percent protein contaminants, including the pneumococcal surface proteins PsaA, PspA and probably PspC. All of these proteins have very high degrees of similarity, using very stringent criteria, with several SARS-CoV-2 proteins including the spike protein, membrane protein and replicase 1a. CRM197 is also present in Hib and meningitis vaccines. Equivalent similarities were found at lower rates, or were completely absent, among the proteins in diphtheria, tetanus, pertussis, measles, mumps, rubella, and poliovirus vaccines. Notably, PspA and PspC are highly antigenic and new pneumococcal vaccines based on them are currently in human clinical trials so that their effectiveness against SARS-CoV-2 disease is easily testable.

The world is currently going through a serious pandemic of viral infection with SARS-CoV-2, a new isolate of coronavirus, resembling and surpassing the crisis that occurred in 2002 and 2013 with SARS and MERS, respectively. SARS-CoV-2 has currently infected more than 142,000 people, causing 5,000 deaths and reaching more than 130 countries worldwide. The very large spreading capacity of the virus clearly demonstrates the potential threat of respiratory viruses to human health, alarming governments around the world that preventive health policies and scientific research are pivotal to overcoming the crisis. Coronavirus disease 2019 (COVID-19) causes flu-like symptoms in most cases. However, approximately 15% of patients will need hospitalization, and 5% require assisted ventilation, depending on the cohorts studied. What is intriguing, however, is the higher susceptibility of elderly individuals, especially those who are more than 60 years old and have comorbidities, including hypertension, diabetes and heart disease. In fact, the death rate in this group may be up to 10-12%. Interestingly, children are somehow protected and not included as a risk group.Thus, here, we discuss some possibilities of molecular and cellular mechanisms by which elderly subjects may be more susceptible to severe COVID-19. In this sense, we raise two main points: i) increased ACE-2 expression in pulmonary and heart tissue of chronic angiotensin 1 receptor (AT1R) blocker users and hypertensive individuals and ii) antibody-dependent enhancement (ADE) after previous exposure to other circulating coronaviruses. We believe these are pivotal points for a better understanding of the pathogenesis of severe COVID-19 and must be addressed with attention by physicians and scientists in the field.

We study here what can be learned from our experience with COVID-19 vaccination for an initially naïve population, that can inform planning for vaccination against the next novel, highly transmissible pathogen. We focus on the first two pandemic years (wild strain through Delta), because after the Omicron wave in early 2022, few people were still SARS-CoV-2-naïve. Almost all were vaccinated, infected, or often both. We review the evidence on COVID-19 vaccine effectiveness (VE), waning effectiveness over time, and what we should expect about VE and waning from a future pathogen. As a basis for our analysis, we conducted a PRISMA-compliant review of all studies on PubMed through August 15, 2022 reporting VE against four endpoints: any infection, symptomatic infection, hospitalization, and death, for the four principal vaccines used in developed Western countries (BNT162b2, mRNA1273, Ad26.CoV2.S, and ChAdOx1-S). The mRNA vaccines (BNT162b2, mRNA1273) had high initial VE against all endpoints but protection waned after approximately six months, with BNT162b2 declining faster than mRNA1273. Both mRNA vaccines initially outperformed the viral vector vaccines. A third “booster” dose, roughly six months after the primary doses, substantially reduced symptomatic infection, severe disease, and mortality, and in hindsight should be seen as part of the normal vaccination schedule.

The immunization of healthcare workers in the early stages of the rollout of COVID-19 vaccines was prioritized in order to ensure uninterrupted medical care provision. At the same time the increasing number of available COVID-19 vaccines may trigger hesitancy towards the decision to get vaccinated. Thus, accumulating reliable information on the adverse events following immunization may educate and urge the general population to receive a COVID-19 vaccine. The present study aimed to evaluate the adverse events (AEs) following immunization with any of the available COVID-19 vaccine among Bulgarian healthcare workers (HCWs). A cross-sectional study among HCWs in Plovdiv, Bulgaria was conducted in the period March – September 2021. Through a semi-structured online questionnaire, the participants reported the adverse events following the administration of the first and second dose of a COVID-19 vaccine. A total of 253 respondents, vaccinated with one of the available vaccines against COVID-19 took part in the study. Of them 71.9% were females, and 75.9% received mRNA-based vaccines, while 24.1% received a viral-vector based vaccine. Overall 91.6% and 82.6% of all participants reported at least one local AE after the first and second dose of a COVID-19 vaccine. The share of respondents reporting at least one systemic AE after the first and second dose of a COVID-19 vaccine was 59.7% and 62.4% respectively. The most common local AE was pain at the injection spot (84.0%), while the most common systemic AEs were fatigue (54.9%), chills (43.2%), and headache (41.7%). The mRNA-based vaccines versions seem to cause higher prevalence of local AEs, while the vector-based vaccines were linked with increased prevalence of systemic AEs. Female HCWs and the younger age group were associated with an increased risk of adverse events generally. Our results added more evidence that mRNA-based and viral-vector based vaccines are generally safe. The reported adverse events were mild, although they occurred in a high share of the respondents. No serious AEs attributable to the vaccines were reported.

Ever since the tremendous success of the rapid vaccine development against COVID‑19, its availa-bility, distribution, and deployment have been a significant concern; however, evidence suggests that vaccine hesitancy has become a greater problem. Therefore, trust in vaccines is crucial and critically dependent on regimes' ability to communicate the benefits of immunization. This study investigated ideas on ways to reduce barriers to COVID-19 vaccination uptake. It explores methods to overcome COVID-19 vaccine barriers through qualitative research: interviews and group discussions involving healthcare providers, administration personnel, teachers, and individuals with chronic conditions across urban (Mombasa) and rural (Kilifi) Kenya. Audio-recorded discussions were transcribed and thematically analyzed across locations. Five themes emerged in our results regarding how to reduce barriers to the COVID vaccine in the context of Kenya, including awareness campaigns, engaging diverse stakeholders, using various communication techniques, capacity building to increase vac-cination centers and trained staff, and lastly, revising relevant government health policies and guidelines. These results indicate the importance of adopting multiple approaches, as no single strategy could boost vaccine acceptance. Moreover, this study provides recommendations for con-ceiving actionable interventions to potentially boost vaccine demand and maintain routine immun-ization in Kenya.

: Background: Vaccine-related death is one of the leading causes of death among African Children. Vaccine coverage is a very important measure to decrease infant mortality. Covid-19 Pandemic has affected the healthcare system and may have disrupted vaccine coverage. Methods: DTP third doses (DTP3) Vaccine Coverage was extracted from UNICEF databases from 2012 to 2021( the last available date). Joinpoint regression was performed to detect the point where the trend changed. The annual percentage change (APC) with 95% confidence intervals (95% CI) was calculated for Africa and the regions. We compared DTP3 vaccination coverage in 2019 with 2021 in each country to verify compliance with WHO targets. Result: During the whole period, the vaccine coverage in Africa has increased with an Annual Percent change of 1.2% (IC 95% 0.9-1.5): We detected one Joint point in 2019. In 2019-2021, there was a decrease in DTP3 coverage with an APC of -3.5(95% -6.0;-0,9). (P< 0.001). Vaccination rates have decreased in many regions and countries during the last two years. Conclusions. COVID-19 has disrupted vaccine coverage, decreasing it all over Africa.

This prospective cohort study aimed to evaluate the efficacy of COVID-19 vaccine schemes, ho-mologous versus heterologous vaccine strategies, and vaccine-induced anti-S-RBD-IgG antibody response in preventing COVID-19 among 942 healthcare workers one year after vaccination with the inactivated and/or mRNA vaccines. All participants received the first two primary doses of vaccines, 13.6% of them lacked the dose-3, 50.5% the dose-4, and 90.3% the dose-5. Antibody lev-els increased with the increase in number of vaccine doses and also in heterologous vaccine regi-mens. In both inactive and mRNA vaccines, infection rates were significantly higher in 2-dose-receivers, but lower in 4- or 5-dose receivers and increasing the total number of vaccine doses resulted in more protection against infection: the 3-dose regimen yielded 4.71 times more protection, the 4-dose 11.76 times and 5-dose 38.46 times more protection from COVID-19 infec-tion, compared to any 2-dose vaccination regimens. Antibody levels at the end of the first year of 4- or 5-dose-receivers were significantly higher than 2- or 3-dose-receivers. To conclude; increased number of total vaccine doses and anti-S-RBD antibody levels increased the protection from COVID-19 infection. Therefore, four or more doses are recommended in one year, for effective protection, especially in risk groups.

Background: Health Care Workers (HCWs) are at increased risk of acquiring and transmitting COVID-19 infection. Also, they present role models for communities with regards to attitudes towards COVID-19 vaccination. Hence, hesitancy of HCWs towards vaccination can crucially affect the efforts aiming to contain the pandemic. Previously published studies paid little attention to HCWs in Arab countries, which has a population of over 440 million. Objectives: to assess the rates of COVID-19 vaccine hesitancy in Arabic-speaking HCWs residing in and outside the Arab countries, and their perceived barriers towards vaccination. Methods: a cross-sectional study based on an online survey was conducted from 14-Jan 2021 to 29-Jan 2021, targeting Arabic-speaking HCWs from all around the world. Results: the survey recruited 5,708 eligible participants (55.6% males, 44.4% females, age 30.6±10 years) from 21 Arab countries (87.5%) and 54 other countries (12.5%). Our analysis shows a significant rate of vaccine hesitancy among Arabic-speaking HCWs residing in and outside Arab countries (25.8% and 32.8%, respectively). The highest rates of hesitancy were among participants from the west region of the Arab world (Egypt, Morocco, Tunisia, and Algeria). The most cited reasons for hesitancy were concerns about side effects and distrust in vaccine expedited production and healthcare policies. Factors associated with higher hesitancy included age of 30-59, previous or current suspected or confirmed COVID-19, female gender, not knowing the vaccine type authorized in the participant’s country, and not regularly receiving the influenza vaccine. Conclusion: this is the first large-scale, multinational, post-vaccine-availability study on COVID-19 vaccine hesitancy among HCWs. It reveals high rates of hesitancy among Arab-speaking HCWs. Unless addressed properly, this hesitancy can impede the efforts for achieving widespread vaccination and collective immunity.

A SARS-CoV receptor-binding domain (RBD) recombinant protein was developed and manufactured under current good manufacturing practices in 2016. The protein known as RBD219-N1 when formulated on Alhydrogel®, induced high-level neutralizing antibodies and protective immunity with minimal immunopathology in mice after a homologous virus challenge with SARS-CoV (MA15 strain). In this report, we examined published evidence in support of whether the SARS-CoV RBD219-N1 could be repurposed as a heterologous vaccine against Coronavirus Infectious Disease (COVID)-19. Our findings include evidence that convalescent serum from SARS-CoV patients can neutralize SARS-CoV-2. Additionally, a review of published studies using monoclonal antibodies (mAbs) raised against SARS-CoV RBD and that neutralize the SARS-CoV virus in vitro, finds that some of these mAbs bind to the receptor-binding motif (RBM) within the RBD, while others bind to domains outside this region within RBD. This information is relevant and supports the possibility of developing a heterologous SARS-CoV RBD vaccine against COVID-19, especially due to the finding that the overall high amino acid similarity (82%) between SARS-CoV and SARS-CoV-2 spike and RBD domains is not reflected in RBM region (59%). However, the high similarity (94%) in the region outside of RBM offers the potential of conserved neutralizing epitopes between both viruses.

The severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) Omicron variant of concern has been the dominant cause of worldwide COVID-19 cases since 2022. All the Omicron sublineage viruses have demonstrated high transmissibility and an ability to escape vaccine-induced immunity. While first-generation vaccines, including monovalent vaccines, continue to provide protection against severe disease, hospitalization and mortality, their efficacy against Omicron sub variants remains sparse. These vaccines have also been associated with rapidly waning protection against primary COVID-19 and COVID-19 reinfections conferred by evolving Omicron sublineages.. This led to the development and deployment of updated vaccines and the introduction of the bivalent booster. Through this review, we highlight the brief journey of the variants of concern leading to the dominance of Omicron and the effectiveness of the key vaccines against these variants, including the updated (bivalent) boosters.

Objectives: To study the differences between malignant hypermetabolic axillary lymphadenopathy (MHL) and COVID-19 vaccine-associated axillary hypermetabolic lymphadenopathy (VAHL) using clinical imaging. Methods: A total of 1,096 patients underwent Positron Emission Tomography-Computed Tomography (PET-CT) between June 1, 2021 and April 30, 2022, at Ehime University Hospital. In total, 188 patients with axillary lymphadenopathy after the COVID-19 vaccination were evaluated. The patients were classified into three groups such as VAHL (n=27), MHL (n=21), and equivocal hypermetabolic axillary lymphadenopathy (EqHL; n=140). Differences in lymph nodes (LNs) swellings were statistically analyzed using clinical imagings (echography, CT, and 18F-FDG PET) statistically. Results: MHL included a higher female population (90.5%) owing to a higher frequency of breast cancer frequency (80.9%). Axillary LNs of MHL did not show any LN fatty hilums (0%); however, those of VAHL and EqHL did (15.8 and 36%, respectively). After the logistic regression analysis of the patients who had axillary lymphadenopathy without any LN fatty hilums, the minor axis length and ellipticity (minor axis/major axis) in the largest axillary LN, SUVmax, and Tissue-to-Background Ratio (TBR) were useful in distinguishing malignant lymphadenopathies. Receiver-operating characteristic (ROC) analysis indicated that a cut-off value of ≥7.3 mm for the axillary LN minor axis (sensitivity: 0.714, specificity: 0.684) and of ≥0.671 for ellipticity (0.667 and 0.773, respectively) in the largest LN with the highest SUVmax and TBR were predictive of MHL. Conclusion: Axillary lymphadenopathy ≥7.3 mm of the minor axis and ≥0.671 of ellipticity in LN without fatty hilum suggests malignancy even in patients who have received COVID-19 vaccination. Further examinations such as 18F-FDG PET are recommended for such patients

(1) Background: Various cutaneous adverse drug reactions (ADRs) are observed with the development of mRNA COVID-19 vaccines. To gain insight into the clinicopathologic features, we analyzed the correlation of histological and clinical data in 48 patients with these ADRs.; (2) Methods: Single-center retrospective study in patients with ADRs post-mRNA COVID-19 vaccination (mRNA-1273 and BNT162b2 vaccines).; (3) Results: Distant generalized ADRs prevailed (91%), often appearing clinically as spongiotic dermatitis or maculo-papular exanthema. Histopathological analysis revealed spongiotic changes (46%) and dermal superficial perivascular lympho-histiocytic infiltrates (17%). Eosinophils were found in 66% of biopsies, neutrophils in 29%, and plasma cells only in 8% of biopsies. Most ADRs occurred post-second vaccine dose (44%). Histologically spongiotic changes were associated with clinical features of spongiotic dermatitis in only 50% and maculo-papular exanthema in the remaining patients. ADRs represented an aggravation of preexisting skin disease in 23% of patients. ADRs regressed within 28 days or less in 53% of patients and persisted beyond a month in the remaining patients.; (4) Conclusions: Our study demonstrates a diverse spectrum of generalized ADRs, revealing correlations between histology and clinical features but also instances of divergence. The majority of ADRs are self-limited with a few extending beyond a month.

Researchers and organizations are pursing 100 Day Vaccine Development to reduce the impact of any new pandemic-causing virus. They propose monitoring viral emergence and developing vaccines for discovered viruses which would undergo safety testing in humans. If one of these viruses emerges, phase III trials would then take place. There are two problems with this approach - first, phase III trials are too long for the 100-day goal and second, the virus that emerged might not have been discovered in their surveillance. An alternative approach would be to first develop vaccines for viral families similar to the pan coronavirus vaccines being proposed for next generation COVID vaccines. Phase III trials for them would be run even if a virus in the family wasn’t having an outbreak. If a virus in a family for which a vaccine has been developed has an outbreak and the phase III trialed vaccine is not effective against it, develop a booster based on the phase III trialed vaccine. Since booster development and approval takes less than 100 days, the 100 Day Vaccine Development goal would be met.

Background Healthcare workers (HCWs) have suffered considerable morbidity and mortality during the COVID-19 pandemic. Few data on COVID-19 vaccine effectiveness (VE) are available from middle-income countries in Europe. We evaluated primary series COVID-19 VE against laboratory-confirmed COVID-19 among HCWs in Georgia. Methods HCWs in six hospitals in Georgia were invited to enroll in a prospective cohort study conducted during March 19–December 5, 2021. Participants completed weekly symptom questionnaires. Symptomatic HCWs were tested by RT-PCR and/or rapid antigen test (RAT), and participants were routinely tested for SARS-CoV-2 by RT-PCR or RAT, regardless of symptoms. Serology was collected at enrolment, and quarterly thereafter, and tested by electrochemiluminescence immunoassay for SARS-CoV-2 antibodies. We defined primary series vaccination as two doses of COVID-19 vaccine received ≥14 days before symptom onset. We estimated VE as (1-hazard ratio)*100 using a Cox proportional hazards model with vaccination status as a time-varying covariate. Estimates were adjusted by potential confounders that changed the VE estimate by more than 5%, according to the change-in-estimate approach. Results Overall, 1561/3849 (41%) eligible HCWs enrolled and were included in the analysis. The median age was 40 (IQR: 30-53), 1318 (84%) were female, and 1003 (64%) had laboratory evidence of prior SARS-Cov-2 infection. At enrolment, 1300 (83%) were unvaccinated; By study end, 1082 (62%) had completed a primary vaccine series (69% BNT162b2 (Pfizer-BioNTech); 22% BBIBP-CorV (Sinopharm); 9% other). During the study period, 191(12%) participants had a new PCR- or RAT-confirmed symptomatic SARS-CoV-2 infection. VEa gainst PCR- or RAT- confirmed symptomatic SARS-CoV-2 infection was 58 (95%CI: 41; 70) for all primary series vaccinations, 68% (95%CI: 51; 79) for BNT162b2, and 40% (95%CI: 1; 64) for BBIBP-CorV vaccines. Among previously infected HCWs, VE was 58% (95%CI: 11; 80). VE against medically attended COVID-19 was 52% (95%CI: 28; 68), and VE against hospitalization was 69% (95% CI: 36; 85). During the period of predominant Delta variant circulation (July-December 2021), VE against symptomatic COVID-19 was 52% (95%CI: 30; 66). Conclusions Primary series vaccination with BNT162b2 and BBIBP-CorV was effective at preventing COVID-19 among HCWs, most of whom had previous infection, during a period of mainly Delta circulation. Our results support the utility of COVID-19 primary vaccine series, and the importance of increasing coverage, even among previously infected individuals.

The analysis reported here is unique in that it is the first study of the original data from the Pfizer/BioNTech BNT162b2 mRNA vaccine clinical trial (CA4591001) to be carried out by a group unaffiliated with the trial sponsor. Our study is a forensic analysis of the 38 trial subjects who died between July 27, 2020, the start of Phase 2/3 of the clinical trial, and March 13, 2021, the data end date of their 6-Month Interim Report. Phase 2/3 of the trial involved 44,060 subjects who were equally distributed into two groups and received Dose 1 of either the BNT162b2 mRNA vaccinated or the Placebo control (0.9% normal saline). At Week 20, when the BNT162b2 mRNA vaccine received Emergency Use Authorization from the U.S. FDA, subjects in the placebo arm were given the option to be BNT162b2 vaccinated. All but a few accepted. Surprisingly, a comparison of the number of subject deaths per week during the 33 Weeks of this study found no significant difference between the number of deaths in the vaccinated versus placebo arms for the first 20 weeks of the trial, the placebo-controlled portion of the trial. After Week 20, as subjects in the Placebo were unblinded and vaccinated, deaths among this still unvaccinated cohort of this group slowed and eventually plateaued. Deaths in the BNT162b2 vaccinated subjects continued at the same rate. Our analysis revealed inconsistencies between the subject data listed in the 6-Month Interim Report and publications authored by Pfizer/BioNTech trial site administrators. Most importantly, we found evidence of an over 3.7-fold increase in number of deaths due to cardiovascular events in BNT162b2 vaccinated subjects compared to Placebo controls. This significant adverse event signal was not reported by Pfizer/BioNTech. Potential sources of these data inconsistencies are identified.

Delineating the epidemic of vaccine injury from the coterminous condition long covid is a challenging prospect, but one with many implications not just for treatment, but also has important legal considerations for settlements of vaccine injury. The shared etiological factor of the spike protein in both vaccine injury and long covid make differentiation difficult, and while treatment is largely similar between vaccine injury and long covid, there are important distinctions. Furthermore, diagnostics are important for monitoring treatment progress and assessing the extent of subclinical vaccine injury in population having received a covid-19 vaccine. The development of rigorous diagnostics is an important step towards the recognition of both long covid and vaccine injury, as those suffering these conditions have faced immense challenges in having their conditions recognized, treated, and compensated by insurance companies or national health services.

Background: To our knowledge, the sudden onset of symptomatic pulmonary hypertension after COVID-19 vaccination has not been described. Both cases presented here resulted in functional limitations and likely permanent organ damage. Case Summary: We report two cases of acute onset pulmonary hypertension in previously healthy adult males within three weeks of receiving the second dose of the Pfizer (BNT162b2) mRNA COVID-19 vaccine from different lots. Both patients experienced the sudden onset of severe fatigue and dyspnea on exertion with negative COVID-19 PCR testing. The diagnosis was made by serial transthoracic echocardiography in the first case and by both transthoracic echocardiography and right heart catheterization in the second. Discussion: Pulmonary hypertension is a serious disease characterized by damage to lung vasculature and restricted blood flow through narrowed arteries from the right to left heart. The onset of symptoms is typically insidious, progressive and incurable, leading to right heart failure and premature death. The World Health Organization (WHO) classifies pulmonary hypertension into 5 categories and recently re-defined as a resting mean pulmonary artery pressure greater than 20 mmHg. Sudden onset pulmonary hypertension would only be expected in the settings of surgical pneumonectomy or massive pulmonary emboli with compromise of at least 50% of the lung vasculature.

Traditional vaccines are produced by using weakened or inactivated forms of disease-causing pathogens to produce the target antigen they are designed to protect against. Messenger RNA vaccines are a class of vaccines that employ a minute segment of genetic material, known as messenger RNA (mRNA), which contains directives for the cells in the body to generate a particular protein. This genetic material is synthesized in the laboratory and packaged into a lipid nanoparticle, which protects and helps it enter cells for further protein synthesis. During vaccination with mRNA vaccine, the lipid nanoparticles containing the mRNA are injected into the muscle of vaccinees. Once inside the cells, the mRNA instructs the cells to produce a protein which is then displayed on the surface of the cell, triggering an immune response. During this, the immune system recognizes the displayed protein as foreign and mounts a defense by producing antibodies and activating immune cells to target and eliminate the protein. Furthermore, these immune responses generate a memory cell, facilitating the immune system to promptly react in case of encountering the authentic pathogen as an infection in the future. The mRNA vaccines are flexible and the sequence can be easily synthesized in the lab based on the genetic information of the target pathogen. Additionally, mRNA vaccines can be developed for new strains or variants of the target disease easily. This was particularly evident during the COVID-19 pandemic, where mRNA vaccines like the Pfizer-BioNTech and Moderna vaccines were developed and authorized for emergency use within a year. But currently, available mRNA vaccines require extensive cold chain, antigen delivery, potential immune response variability optimization, and sophisticated manufacturing process. The efforts to explore next-generation mRNA vaccine development are aimed to further improve the effectiveness, stability, and delivery methods. One focus of research has been to enhance the stability of mRNA vaccines, particularly temperature sensitivity which makes storage and distribution easier, particularly in regions with limited access to cold chain infrastructure. Self-amplifying mRNA vaccines, on the other hand, are designed to generate multiple copies of the mRNA within cells which potentially leads to a higher production of the target protein, resulting in a stronger immune response. Additionally, studies are exploring new delivery systems to improve the target and efficiency of mRNA vaccines using specialized nanoparticles and liposomes to specifically deliver mRNA to certain cell types or immune cells. Another area of interest is the development of combination vaccines, where multiple mRNA sequences are included in a single vaccine protecting against multiple diseases targeting strains or variants of a particular pathogen simultaneously. While current mRNA vaccines are administered via intramuscular injection, studies are underway to deliver directly into the skin offering enhanced immune response and the ability to use smaller vaccine doses.

Vaccine hesitancy remains a public health challenge. It has been argued that the sources of vaccine-related information may serve as important condiments to one’s decision to be vaccinated. However, little empirical attention is given to the subject. We contribute to this debate by assessing the level of COVID-19 vaccine hesitancy and the role of information explaining hesitancy, using the Nelson Mandela Bay Municipality of South Africa as a case study. Findings confirm high level of vaccine hesitancy, representing 78.8 percent of the respondents (which is above the national level of 41%). Furthermore, findings reveal that vaccination decisions are influenced by family, which is the most trusted among all institutions in the society, especially on sensitive matters and those shrouded by myths and misinformation. Additionally, the majority trusts health care workers and mass media as sources of health-related and general information; however, the use of popular personalities to convey health information is not supported. The findings reveal key socio-demographic and institutional drivers of COVD-9 vaccine hesitancy, such as age, inadequate information on the vaccine, trust issues, conspiracy beliefs, vaccine-related factors, and perceived side effects associated with the vaccine. Recommendations based on the findings are provided.

The phenomenon of vaccine hesitancy is a growing threat to public health with far-reaching implications. The widening gap between the vaccinated and the proportion needed for herd immunity raises two critical research questions that are of interest to practitioners, researchers, and policymakers: (1) What determines one’s decision to be vaccinated? and (2) What is the implication of COVID-19 vaccine hesitancy on economic recovery? In this study, we use empirical data in the context of South Africa to investigate factors affecting COVID-19 vaccine hesitancy and their implications for economic recovery. Findings reveal key socio-demographic and institutional drivers of COVD-9 vaccine hesitancy, which include age (the youth are more hesitant), inadequate information on the vaccine (those who perceive they have adequate information are vaccinated), trust issues in government institutions, conspiracy beliefs, vaccine-related factors, and perceived side effects associated with the vaccine. Additionally, an individual’s decision to remain hesitant about COVID-19 vaccination has implications for businesses and the economy by limiting movement and trade, increasing unemployment, and causing a resurgence of new variants. Based on the findings, action plans such as information dissemination, convenience vaccination centers, consistency communications, and targeted campaign strategies are recommended for improving vaccine intakes and a positive economic recovery.

Introduction. Covid-19 faced the world with serious health and socioeconomic issues. At the very beginning of the pandemics, the vaccine was considered by health authorities and the medical community the only way to curb the spread of the virus. One of the measures that have been proposed to increase vaccinations was the mandatory policy. The purpose of this study was to compare determinants of voluntary and mandatory vaccination among students of Albanian University. Methodology: This cross-sectional study by means of an online survey, was conducted among students enrolled in the private University “Albanian University”, Tirana, Albania during the last week of winter semester 7-14 Feb 2022. Results: 878 students participated in this study, among them 612 (69.7%) were females, 266 (30%) were males. 506 (57%) of the participants were enrolled in Medical Sciences (MS), 372(42.3%) were Non-Medical Science (Non-MS) group. 773 (88%) was vaccinated against Covid-19, 105 (11.8%) were not vaccinated. 466 (53%) reported voluntary vaccination, 412 (46.9%) reported mandatory vaccination. Among students that vaccinated voluntary 266 (57%) were from MS group, 200(42.9%) from Non-MS group. 237(57.5%) of students in mandatory vaccination group were from MS group, 175 (42.4%) from Non-MS. Conlusion. Vaccine safety and efficacy were hindering factors of vaccination. Also, based on the results of this study, the students felt encouraged to vaccinate by the academic staff. This clearly demonstrates that the staff does not lack the skills to enhance stu-dents' knowledge about the risk of infectious diseases and the importance of vaccination. Therefore, to influence as much as possible students’ attitude toward vaccination, comprehensive educational programs including modification of existing curricula should be considered.

Background Several vaccines have been approved for prevention of the coronavirus disease discovered on 31st December in Wuhan, China. Pakistan procured vaccines from various countries. However, the lack of knowledge and reluctance of the general population to embrace the use of the vaccines are considered to be the major determinants of the slow vaccination rate. Hence, it is necessary to evaluate the willingness of the general population about their perception of the COVID-19 vaccination. Methods A cross sectional survey based on a self-structured questionnaire comprising 18 questions was conducted (from April 21-June 21) on 400 Pakistani participants to evaluate their knowledge, attitude and perception towards the COVID-19 vaccination. Chi-square independent t-test and one-way Anova including a multiple step wise linear regression were used to draw conclusions about the results. P< 0.05 was considered significant. Results A total of 400 participants responded in the KAP survey of which 46.5% were female and 53.5% were male. The mean age of participants was 36.08 years. This survey showed a poor knowledge (50.5%), a fair attitude (75.1%) and a poor perception (58.1%) towards the COVID-19 vaccination. Higher mean knowledge and attitude scores was reported in the age group 21-40, females and unmarried urban citizens. Regression analysis showed that age, education, residence and employment status influenced the knowledge and perception score to a considerable extent. Conclusions The findings reflect an inadequate knowledge and perception on the one hand but a better attitude towards the COVID-19 vaccination. This KAP survey will help in better understanding the opinion of the general population towards vaccination and will be useful for policy makers and health care authorities aiming to increase the vaccination rate.

Background: This study describes the attitudes and practices of Brazilian adults regarding the mandatory vaccination for COVID-19 and the hesitancy to children´s vaccination. Methods: The participants answered an online questionnaire disseminated on social networks. An adaptation of the SAGE-WG questionnaire was used to measure the children's vaccination hesitancy. Results: Among 1,007 participants, 677 (67.4%) believed that vaccination for COVID-19 among adults should be mandatory. Just over half of the participants (51.5%) believe that parents and guardians should be free to decide whether their children should be vaccinated against COVID-19, and 9.1% were unsure about this. Younger, non-religious people who have higher self-perceptions of risk for COVID-19, and who evaluate the federal government's performance in combating the disease as bad or very bad, have a higher agreement with mandatory vaccination, a lower agreement that parents and guardians should be free to vaccinate their children, and lower child vaccination hesitancy scores. Conclusion: In Brazil, mandatory COVID-19 vaccination for adults is far from a consensus, and an expressive part of the population believes that parents and guardians should be free to choose whether or not to vaccinate their children. These perceptions and vaccine hesitancy for children are associated with religious and political inclinations.

We determined the levels of neutralizing antibodies against the SARS-CoV-2 ancestral strain, Delta and Omicron variants of concern (VOCs) in 125 healthcare workers, who received Coro-naVac as their primary vaccination and later received either a single ChAdOx1 or a combination of two consecutive boosters using either two ChAdOx1 doses or a ChAdOx1 or BNT162b2 as the primary and second boosters, respectively, or 2 doses of BNT162b2. The titers 12 weeks after primary vaccination were inadequate to neutralize the all strains. After a single ChAdOx1 boost-er, the levels of neutralization at Day 30 varied significantly, only a small proportion of partici-pants developing neutralizing titers against Omicron at Day 7 and 30. The two doses of ChA-dOx1 as the booster induced lowest activity. A combination ChAdOx1 and BNT162b2 induced greater neutralization than by two doses of ChAdOx1. Two doses of BNT162b2 as the booster had the maximal activity against Omicron VOC.

The COVID-19 pandemic has highlighted the adverse consequences created by an infodemic specifically on compliance with public health guidance and vaccine uptake. COVID-19 vaccine hesitancy is a complex construct that is related to health beliefs, misinformation exposure, and perceptions of governmental institutions. This study draws on theoretical models and current data on the COVID-19 infodemic to explore the association between perceived risk of COVID-19, levels of misinformation endorsement, and opinions about the government response on vaccine uptake. We surveyed a sample of 2,697 respondents from the US, Canada, and Italy using a mobile platform between 21-28 May, 2021. Using multivariate regression, we found that country of residence, risk perception of contracting and spreading COVID-19, perception of government response and transparency, and misinformation endorsement was associated with the odds of vaccine hesitancy. Higher perceived risk was associated with lower odds of hesitancy, while lower perceptions of government response, and higher misinformation endorsement were associated with higher hesitancy.

The novel coronavirus disease (COVID-19) has created immense threats to public health on various levels around the globe. The unpredictable outbreak of this disease and the pandemic situation are causing severe depression, anxiety and other mental as physical health related problems among the human beings. To combat against this disease, vaccination is essential as it will boost the immune system of human beings while being in the contact with the infected people. The vaccination process is thus necessary to confront the outbreak of COVID-19. This deadly disease has put social, economic condition of the entire world into an enormous challenge. The worldwide vaccination progress should be tracked to identify how fast the entire economic as well as social life will be stabilized. The monitor ofthe vaccination progress, a machine learning based Regressor model is approached in this study. This tracking process has been applied on the data starting from 14^th December, 2020 to 24^th April, 2021. A couple of ensemble based machine learning Regressor models such as Random Forest, Extra Trees, Gradient Boosting, AdaBoost and Extreme Gradient Boosting are implemented and their predictive performance are compared. The comparative study reveals that the AdaBoostRegressor outperforms with minimized mean absolute error (MAE) of 9.968 and root mean squared error (RMSE) of 11.133.

High levels of air pollution can contribute to high rate of the COVID-19 outbreaks. Air pollutants induce oxidative stress, inflammatory process, immune imbalance and coagulation at systemic level, making the organism susceptible to complications caused by various pathogens, including viruses, resulting in a possible important damage co-factor. Sperm cells are highly sensitive to the pro-oxidant effects of environmental pollutants, and may represent an important alarm bell indicating that the burden of environmental pressure in a certain area is causing damage to humans. A comparison of the maps of COVID-19 case fatality rates, male infertility rates and air pollution may suggest a way to understand the dynamics of the virus impact. Semen quality may be considered as an early and sensitive environmental marker, and also a potential susceptibility indicator to viral insults (including SARS-CoV-2 ) in heavily polluted areas. Therefore, assessing the burden of environmental exposure of a given population and its potential susceptibility to insults through early biological stress indicators may be helpful for predicting the risk of the adverse effects by the SARS-CoV-2 epidemic .

In Italy HPV vaccination was implemented for girls since 2007 but its coverage was lower than recommended level. Sicily is one of the Italian administrative regions with lower vaccination coverage, ranging in the birth cohorts 1996–1999 from 59% to 62%. Aim of the study was to investigate factors associated with refusal of anti-HPV vaccination among young adult women of Palermo, Italy. A cross-sectional study was conducted through the administration of a telephone questionnaire, consisting of 23 items on HPV infection and vaccination knowledge based on Health Belief Model framework. The eligible population were young women with at least a previous vaccination among all included in Sicilian Vaccination schedule, without starting or completing anti-HPV vaccination schedule. Overall, 141 young women were enrolled, of them 84.4% were unvaccinated and 15.6% had at least one dose of HPV vaccine. In multivariate analysis, factors associated with the failure to perform the HPV vaccination were degree as school level (OR = 10.2, p = 0.041), lower participation at school seminar on HPV (OR = 0.2, p = 0.047) and lower perception of anti-HPV vaccine benefits (OR = 0.4, p = 0.048). Public health educational program focusing and tailored on benefits perception of anti-HPV vaccine and HPV disease severity, especially if carried out at school, can improve HPV vaccination uptake.

With the COVID-19 pandemic now ongoing for close to a year, people all over the world are still waiting for a vaccine to become available. The initial focus of accelerated global research and development efforts to bring a vaccine to market as soon as possible was on novel platform technologies that promised speed but had limited history in the clinic. In contrast, recombinant protein vaccines, with numerous examples in the clinic for many years, missed out on the early wave of investments from government and industry. Emerging data are now surfacing suggesting that recombinant protein vaccines indeed might offer an advantage or complement to the nucleic acid or viral vector vaccines that will likely reach the clinic faster. Here, we summarize the current public information on the nature and on the development status of recombinant subunit antigens and adjuvants targeting SARS-CoV-2 infections.

Background: Vaccinating children against COVID-19 is an essential public health approach for preventing infection in children and adults. This study aimed to explore parents' attitudes toward and the rate of COVID-19 vaccine hesitancy among children in Oman. Methods: This cross-sectional study used an online, self-administered questionnaire. The 9-item questionnaire was validated earlier and administered between June 2021 and May 2022. Multiple logistic regression was used to determine the factors associated with vaccine hesitancy. The parents received a pre-validated Google questionnaire. Responses from the parents of children younger than 11 years of age were accepted. Results: 384 participants completed the questionnaire, including 207 males (54%). The response rate was 86% (384/447). Of the 384 participants, 69% of the parents hesitated to vaccinate their children aged 1-11-year-old children). In parents of children aged 1–4 years, parental vaccination status was significantly associated with vaccine hesitancy (odds ratio [OR]: 0.116, 95% confidence interval [CI]: 0.044–0.306; p < 0.001). Additionally, vaccine hesitancy was significantly more common in mothers than in fathers (OR: 0.451, 95% CI: 0.240–0.848; p = 0.013). . Mothers of children were 77% more likely to be hesitant than fathers (.78, 95% confidence intervals (CI) = 0.50–0.1.23; p = 0.283). Conclusion: Many parents hesitated to vaccinate their children against COVID-19. Consequently, future awareness campaigns and strategies should target new vaccines. The results of our study show that the Arabic version of the 5-point Likert Scale for Vaccination Hesitancy is a valid and reliable tool.

Background: COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a recurrent endemic disease affecting the whole world. Since November 2021, Omicron and its subvariants are dominating. In order to prevent severe courses of disease, vaccines are needed to boost and maintain antibody levels capable of neutralizing Omicron. Recently we produced and characterized a SARS-CoV-2 vaccine based on a recombinant fusion protein consisting of hepatitis B virus (HBV)-derived PreS and two SARS-CoV-2 wild-type RBDs. Objectives: To develop a PreS-RBD vaccine which induces high levels of Omicron-specific neutralizing antibodies. Methods: We designed, produced, characterized and compared strain-specific (wild-type: W-PreS-W; Omicron: O-PreS-O), bivalent (mix of W-PreS-W and O-PreS-O) and chimeric (i.e., W-PreS-O) SARS-CoV-2 protein subunit vaccines. Immunogens were characterized in vitro by protein chemical methods, mass-spectrometry, circular dichroism in combination with thermal denaturation and immunological methods. In addition, BALB/c mice were immunized with aluminum hydroxide-adsorbed proteins and aluminum hydroxide alone (i.e., placebo) to study specific antibody and cytokine responses, safety and Omicron neutralization. Results: Defined and pure immunogens could be produced in large amounts as secreted and folded proteins in mammalian cells. Antibodies induced after vaccination with different doses of strain-specific, bivalent and chimeric PreS-RBD fusion proteins reacted with wild-type and Omicron RBD in a dose-dependent manner and resulted in a mixed Th1/Th2 immune response. Interestingly, RBD-specific IgG levels induced by the different vaccines were comparable but the W-PreS-O-induced virus neutralization titers against Omicron (median VNT50: 5000) were 7- and 2-fold higher than the W-PreS-W- and O-PreS-O-specific ones, respectively and 6-fold higher than those of the bivalent vaccine. Conclusion: Among the tested immunogens, the chimeric PreS-RBD subunit vaccine, W-PreS-O, induced the highest neutralizing antibody titers against Omicron. Thus, W-PreS-O seems to be a highly promising COVID-19 vaccine candidate for further preclinical and clinical evaluation.

Background: To describe the effectiveness and safety of COVID-19 vaccine in a series of patients with rheumatoid arthritis (RA). Methods: Retrospective single-center study of RA patients, fulfilling the ACR 1987 or ACR/EULAR 2010 classification criteria, that received first COVID-19 vaccine between December 2020 and October 2021, had post-vaccination serology and subsequent follow-up of at least 6 months in a university hospital. Vaccine effectiveness was evaluated by the serological response and the incidence of post-vaccine COVID-19, and safety by the incidence of adverse events (AE) and RA flares. Adjusted logistic and linear multivariate regression analyses were carried out with Stata® to identify factors associated with vaccine response. Results: We included 118 patients with RA (87.2% women, age 65.4±11.6 years, evolution 12.0±9.6 years). 95.8% received complete vaccination schedule. Most patients (88.1%) developed adequate humoral immunogenicity, and the degree of serological response was significantly related to younger age and previous COVID-19 infection. After vaccination, 18.6% presented mild SARS-CoV-2 infection. Vaccine AE (19.5%) were mostly mild and inversely associated with age (OR 0.95). RA flares were anecdotal (1.7%) and inversely related to age (OR 0.95). Conclusion: Our results suggest that COVID-19 vaccine induces adequate humoral immunogenicity, with an acceptable safety profile in RA patients.

(1) Background: We previously reported the development of a recombinant protein SARS-CoV-2 vaccine, consisting of the Receptor-Binding Domain (RBD) of the SARS-CoV-2 spike protein, adjuvanted with aluminum hydroxide (alum) and CpG oligonucleotides. In mice and non-human primates, our wild-type (WT) RBD vaccine induced high neutralizing antibody titers against the WT isolate of the virus, and, with partners in India and Indonesia it was later developed into two closely resembling human vaccines, Corbevax and Indovac. Here, we describe the development and characterization of a next-generation vaccine adapted to the recently emerging XBB variants of SARS-CoV-2. (2) Methods: We conducted preclinical studies in mice using a novel yeast-produced SARS-CoV-2 XBB.1.5 RBD subunit vaccine candidate formulated with alum and CpG. We examined the neutralization profile of sera obtained from mice vaccinated twice intramuscularly at a 21-day interval with the XBB.1.5-based RBD vaccine, against WT, Beta, Delta, BA.4, BQ.1.1, BA.2.75.2, XBB.1.16, XBB.1.5 and EG.5.1 SARS-CoV-2 pseudoviruses. (3) Results: The XBB.1.5 RBD/CpG/alum vaccine elicited a robust antibody response in mice. Furthermore, serum from vaccinated mice demonstrated potent neutralization against the XBB.1.5 pseudovirus as well as several other Omicron pseudoviruses. However, regardless of high antibody cross-reactivity by ELISA, the anti-XBB.1.5 RBD antigen serum showed low neutralizing titers against the WT and Delta virus variants. (4) Conclusions: Whereas we observed modest cross-neutralization against Omicron subvariants by sera from mice vaccinated with the WT RBD/CpG/Alum vaccine or with the BA.4/5-based vaccine, sera raised against the XBB.1.5 RBD showed robust cross-neutralization. These findings underscore the imminent opportunity for an updated vaccine formulation utilizing the XBB.1.5 RBD antigen.

Introduction: COVID-19 vaccines have been the most effective means in curbing the infection, however, vaccine hesitancy has been seen as a threat to global health. Objective: the study aimed to assess the prevalence and predictors of COVID-19 vaccine hesitancy among healthcare workers in infectious disease centers in Ghana. Method: A cross-sectional study and proportionate stratified sampling method was used to recruit participants from various infectious disease centers. Result: data from 170 participants were analyzed, revealing a low prevalence of COVID-19 vaccine hesitancy (11.2%) among healthcare workers. However, only 31.1% of the fully vaccinated participants had taken the booster dose. Factors such as concerns about vaccine safety and side effects from previous doses, indecisiveness, a lack of time to receive the vaccine and lack of access to accurate information, prefered natural immunity were the significant predictors of vaccine hesitancy among healthcare workers. Participants with good perception of the risk posed by COVID-19 was positively correlated with COVID-19 vaccine acceptance. Conclusion: the study suggests that policies should be enacted to ensure health workers are vaccinated against highly contagious infectious diseases to prevent their spread among the general population. Training and health promotion campaigns should also be organized to encourage healthcare workers to accept and patronize the vaccines.

The coronavirus disease (COVID-19) vaccine is key to reducing the probability of contracting COVID-19. The vaccine is generally known to prevent severe illness, death, and hospitalization as a result of the disease and for considerably reducing COVID-19 infection risk. Accordingly, this might significantly change an individual’s perceived risk of altering everyday behaviors. For instance, the proliferation of vaccination is anticipated to reduce preventive behaviors such as staying at home, handwashing, and wearing a mask. We corresponded with the same individuals monthly for 18 months from March 2020 (early stage of COVID-19) to September 2021 in Japan to independently construct large sample panel data (N=54,007), with a participation rate of 54.7 %. We used a fixed effects model, controlling for key confounders, to determine whether vaccination was associated with a change in preventive behaviors. The major findings are as follows. Contrary to the prediction, (1) based on the whole sample, being vaccinated against COVID-19 led people to stay at home; however, it did not change the habit of handwashing and wearing a mask. Especially after the second shot, respondents were likelier to stay at home by 0.107 (95% CIs: 0.059–0.154) points on a 5-point scale compared to before the vaccination. Dividing the entire sample into young and old, (2) those aged ≤ 40 years were more likely to go out after being vaccinated, and (3) people over 40 years of age were more likely to stay at home (similar to the first result). Preventive behaviors impact all individuals during the current pandemic. Informal social norms motivate people to increase or maintain preventive behaviors even after being vaccinated in societies where these behaviors are not enforced.

The COVID-19 pandemic is a devastating blow to the entire world community and changes the order of human life. All efforts and strategies are being carried out to contain and reduce the spread of the SARS-COV-2 virus, both by tightening the health protocol and using vaccines to the public. Currently, several vaccines are available and have passed phase 3 clinical trials, such as vector vaccines (Gamaleya Sputnik V Russia, University of Oxford/AstraZeneca, CanSino, and Janssen Pharmaceutical Companies), mRNA-based vaccines (Moderna/BioNTech/Fosun Pharma/Pfizer), inactivated vaccines (SinoVac and SinoPharm from China, Covaxin from Bharat Biotech India), and adjuvanted recombinant protein nanoparticles (Novavax from the USA) are expected to be able to suppress the spread of the virus and produce a minimum of 70 percent herd-immunity in a population. Each vaccine's efficacy varies from the lowest, namely the Sinovac vaccine (CoronaVac) 50% to the highest the Novavax vaccine (NVX-Cov2373) 96% effectivity value. Moreover, further rigorous research is still being carried out for the development of an effective and efficient vaccine.

Introduction: The SARS-CoV-2/COVID-19 pandemic has triggered the need for developing rapidly effective and safety vaccines to prevent infection, particularly in those at-risk populations such as medical personnel. The objective of this study was to assess perception of COVID-19 vaccination amongst Colombian physicians featuring two different sceneries of COVID-19 vaccination. Methods: A cross-sectional analytical study was carried out through an online survey, directed at medical staff in several cities in Colombia. The percentage of physicians who have a positive perception to be vaccinated and the associated factors that determine that decision were determined. A binomial regression analysis adjusted for age and sex was carried out, taking as a dependent variable the acceptance of free vaccination with an effectiveness of 60 and 80%. The most significant factors were determined in the non-acceptance of vaccination. Results: Between 77.1% and 90.8% of physicians in Colombia, accept COVID-19 vaccination, according to the scenario evaluated where the effectiveness of the vaccine was 60 or 80%, respectively. Medical specialty, have ever paid for a vaccine, recommend administrating the vaccine to their parents or people over 70 years and dispense the vaccine to their children were the factors to be vaccinated for free with an effectiveness of 60% and 80%. Conclusions: There is a high perception of the intention to vaccinate physicians in Colombia against COVID-19. But it is very similar to that of the general population, according to results reported in other studies.

Knowing the “point of view” of the immune system is essential to understand the characteristic of a pandemic, such as that generated by the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2, responsible for the Coronavirus Disease (COVID)-19. In this review, we will discuss the general host/pathogen interactions dictating protective immune response or immunopathology, addressing the role of immunity or immunopathology in influencing the clinical infection outcome, and debate the potential immunoprophylactic and immunotherapy strategies required to fight the virus infection.

The Covid-19 infodemic can be countered by scientific evidences, clear and consistent communication and improved health literacy of both individuals in need of information and those providing it. A rapid online survey was carried out to evaluate vaccine literacy (VL) skills in the general population and perceptions about candidate Covid-19 vaccines, as well as behavior and beliefs about current vaccinations. Observed VL levels were sufficiently high and consistent with previous observations - where comparable self-reported tools were administered face-to-face and paper-and-pencil - the mean functional score being =2.92, while the interactive-critical one was =3.27, on a maximum of 4. Perceptions regarding future Covid-19 vaccines, along with beliefs about vaccination, were mostly positive and significantly associated with functional and interactive-critical VL scales. Despite obvious limitations, the study confirms that rapid surveys via web are a suitable method to evaluate and trail attitudes during infectious disease outbreaks, and to assess health literacy skills about vaccination, which can be useful to adapt medical communication strategies, for a better understanding of the value of immunization.

We review aspects of the antibody response to SARS-CoV-2, the causative agent of the COVID- 19 pandemic. The topics we cover are relevant to immunotherapy with plasma from recovered patients and with monoclonal antibodies against the viral S-protein. The development of vaccines against SARS-CoV-2, an essential public health tool, will also be informed by an understanding of the antibody response in infected patients. Although virus-neutralizing antibodies are likely to protect, antibodies could potentially trigger immunopathogenic events in SARS-CoV-2-infected patients or enhance infection. An awareness of these possibilities may benefit clinicians and the developers of antibody-based therapies and vaccines.

The SARS-CoV-2 is a recently identified positive sense single stranded RNA virus and member of the coronavirus family of viruses. It is thought to be the etiological factor for the ongoing COVID-19 pandemic. This virus is thought to have originated from bats and acquired ability of human-to-human transmission. While SARS-CoV-2 is relatively benign, it has infected more than half a million people (as of March 29^th 2020) worldwide and the number of infected people continues to rise. More than 170 countries have reported COVID-19 positive cases. With a mortality rate of less than both the previous coronavirus outbreaks, COVID-19 has (conversely) caused the death of over 33,980 (as of 29^th March, 2020 at 22.00 hours EDT) people worldwide and the number is increasing. Given the enormous impact of this virus on human health and wellbeing and consequent devastating impacts on world trade, economics and quality of life, it is important to understand this virus better and get insight into its pathogenic mechanisms which will aid in devising effective measure to curb its spread and predict future pattern of its interaction with humans. Though very little is known about this SARS-CoV-2 but its mechanisms and patterns of spread can be speculated (with caution, nevertheless) from what we know about its closest relatives SARS-CoV-1 (responsible for SARS-2002 epidemic) and MERS-CoV (responsible for MERS-2012 epidemic). In the present review, we aim at bringing together the coherent and peer reviewed literature about the SARS-CoV-2 and its close relatives and try to understand its infection patterns and reconstruct its pathogenic mechanisms with anecdotes on diagnosis and future directions. We hope that this paper will serve the purpose of being a reliable source of information to scientists, clinicians and general public.

Management of inflammatory bowel disease (IBD) often relies on biological and immunomodulatory agents for remission through immunosuppression, raising concerns regarding the SARS-CoV-2 vaccine's effectiveness. The emergent variants have hindered the vaccine neutralization capacity, and whether the third vaccine dose has the capacity to neutralize SARS-CoV-2 variants in this population remains unknown. This study aims to evaluate the humoral response of SARS-CoV-2 variants in patients with IBD 60 days after the third vaccine dose [BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna)].56 su bjects with IBD and 12 healthy subjects were recruited. 90% of patients with IBD (49/56) were receiving biologics and/or immunomodulatory therapy. 24 subjects with IBD did not develop effective neutralizing capability against the Omicron variant. 70% (17/24) of those subjects were receiving anti-Tumor Necrosis Factor therapy [10= adalimumab, 7= infliximab], two of them had a history of COVID-19 infection, and one subject did not develop immune neutralization against three other variants: Gamma, Epsilon, and Kappa. All subjects in the control group developed detectable antibodies and effective neutralization against all seven SARS-CoV-2 variants. Our study shows that patients with IBD might not be protected against SARS-CoV-2 variants, and larger studies are needed to evaluate optimal immunity.

Pregnant women have been considered a high-risk group for SARS-CoV-2 infection; the impact of the disease on the health of a mother and her child is still being studied. The emotional impact of the pandemic on pregnant women has been extensively studied. Emotional distress is proposed as a perspective to explain the emotional manifestations of women during this stage as something common rather than pathological. The objective of this study was to know the emotional experience of women who tested positive for SARS-CoV-2 towards the end of their pregnancy, during the first and second waves of COVID in Mexico. A qualitative study was carried out: 18 pregnant women with COVID were interviewed. A thematic analysis of the data was performed, resulting in three main themes and 14 subthemes. The COVID-infected mothers-to-be experienced mild to moderate emotional distress. It was more intense for those with comorbidities. This distress was aggravated during obstetrical complications and comorbidities, as well as during COVID and postpartum. The emotional distress was appeased by both the perception of medical care and social support. The emotional distress of pregnant women with COVID requires emotional accompaniment to reduce its impact.

Rapid development and deployment of vaccines greatly reduced mortality and morbidity during the COVID-19 pandemic. The most widely used COVID-19 vaccines approved by national regulatory authorities require intramuscular administration. SARS-CoV-2 initially infects the upper respiratory tract where the infection can be eliminated with little or no symptoms by an effective immune response. Failure to eliminate SARS-CoV-2 in the upper respiratory tract results in lower respiratory tract infections that can lead to severe disease and death. Presently used intramuscularly administered COVID-19 vaccines are effective in reducing severe disease and mortality but are not entirely able to prevent asymptomatic and mild infections as well as person to person transmission of the virus. Individual and population differences also influence susceptibility to infection and the propensity to develop severe disease. This article provides a perspective on the nature and the mode of delivery COVID-19 vaccines that can optimize protective immunity in the upper respiratory tract to reduce infections and virus transmission as well as severe disease.

Human papillomavirus (HPV) infection is a widespread sexually transmitted infection linked to various types of cancers. Although vaccination against HPV is available, global HPV vaccination rates remain low. This study aimed to evaluate the awareness and knowledge of the HPV vaccine and to identify predictors associated with vaccine hesitancy among health college students in Saudi Arabia. A cross-sectional survey was distributed to students enrolled in health colleges. The association of vaccine hesitancy with sociodemographic characteristics was examined using logistic regression analysis. The study found that approximately half of the students (49.9%) were aware of the HPV vaccine. Students from the College of Medicine showed the highest level of knowledge. Only a small proportion (5.2%) reported receiving the vaccine. The overall HPV vaccine hesitancy was 59.1% (43.9% for women and 75.9% for men). The most common reasons for vaccine hesitancy was not knowing enough about it. Men were twice as likely as women to believe that they did not need the HPV vaccine. The odds for HPV vaccine hesitancy were greater among men and younger age group compared to women and older age group. In conclusion, the study underscores the importance of awareness campaigns on HPV vaccination, targeting primarily male students.

Background: Comorbidities have been frequently reported in COVID-19 patients, which often lead to more severe outcomes. The underlying molecular mechanisms behind these clinical observations have not yet been explained. Herein, we investigated the disease-specific gene expression signatures that may induce susceptibility to SARS-CoV-2 infection. Methods: We studied 30 frequently occurring acute, chronic, or infectious diseases of recent times that have shown comorbidity in one or another respiratory disease(s) caused by pathogenic human infecting coronaviruses, especially SARS-CoV-2. We retrieved array-based gene expression data for each disease and control from relevant datasets. Subsequently, all the datasets were quantile normalized, and log-2 transformed data was used for analysis. Results The expression of ACE2 receptor and host proteases, namely FURIN and TMPRSS2 that are essential for cellular entry of SARS-CoV-2, was upregulated in all six studied subtypes of leukemia (hereafter, referred as leukemia). The expression of ACE2 was also increased in psoriasis, lung cancer, Non-alcoholic fatty liver disease (NAFLD), breast cancer, and pulmonary arterial hypertension patients. The expression of FURIN was higher in psoriasis, NAFLD, lung cancer, and in type II diabetic liver, whereas it was lowered in breast cancer. Similarly, the expression of TMPRSS2 was increased during lung cancer and type II diabetes; it was decreased during psoriasis, NAFLD, lung cancer, breast cancer, and cervical cancer.Furthermore, a heightened expression of genes that are involved in immune response was observed in leukemia patients, as shown by the higher expression of IFNA2, IFNA8, IFNA10, IFNA14, IFNA16, IFNA21, IFNB1, CXCL10, and IL6. The expression of JAK1, STAT1, IL6, and CXCL10 was higher in NAFLD. Besides, JAK1 and STAT1 were upregulated in type II diabetic muscles. In addition, most of the upregulated genes in COVID-19 patients showed a similar trend in leukemia, NAFLD, and psoriasis. Furthermore, SARS-CoV-2, SARS-CoV and MERS CoV, were found to commonly alter two genes, namely, CARBONIC ANHYDRASE 11 and CLUSTERIN.Conclusions: The genes that may confer susceptibility to SARS-CoV-2 infection are mostly upregulated in leukemia patients; hence, leukemia patients are relatively more susceptible to develop COVID-19, followed by other chronic disorders, such as, NAFLD, type II diabetes, psoriasis, and hypertension. This study identifies key genes that are altered in the studied diseases types, which may aid in the infection of SARS-CoV-2 and underlie COVID-19 associated comorbidities.

Background: In America, vaccine-related deaths constitute a significant contributor to child mortality. An essential means of reducing this is through broad vaccine coverage. The COVID-19 pandemic has posed a potential disruption to vaccine coverage due to its effects on the healthcare system. Objectives: This study aims to evaluate the impact of the COVID-19 pandemic on DTP3 vaccination coverage in the Americas, investigating trends from 2012 to 2022 to identify significant changes, regional disparities, and the overall effect of the pandemic on progress towards global immunization targets. Methods: This study used the coverage data for the third dose of the Diphtheria, Tetanus, and Pertussis Vaccine (DTP3) pulled from UNICEF databases spanning 2012 to 2022. We conducted a JoinPoint regression to identify points of significant trend changes. The annual percentage change (APC) and 95% confidence intervals (95% CI) were calculated for America and its regions. We also used segmented regression analysis. Using the Chi-square test, we compared DTP3 vaccination coverage for each country between 2019 and 2022. Results: Overall, America saw a decrease in vaccine coverage during this period, with an APC of -1.4 (95% CI -1.8.; -1.0). This trend varied across regions. In North America, the decrease was negligible (-0.1% APC). South America showed the steepest decrease, with an APC of -2.5%. Central America also signif-icantly declined, with an APC of -1.3%. Our findings suggest a concerning trend of declining DTP vaccination rates in the Americas, exacerbated in certain regions, in the wake of the COVID-19 pandemic. The absolute decrease in vaccine coverage in the Americas was -4 % between 2019 and 2022, with the most significant drop observed in Central America (-7 %). However, six countries reported increased vaccination rates post-COVID-19, led by Brazil, with a 7% increase. Conversely, twenty-two countries registered a decline in DTP3 vaccine coverage, with the average decrease being -7.37%. This decline poses a significant challenge to achieving the WHO's target of 90% coverage for the third dose of DTP by 2030, as evidenced by the reduction in the number of countries meeting this target from 2019 to 2022. Conclusions: The COVID-19 pandemic has impacted vaccine coverage in America, leading to a decrease, especially across Central America.

Background: COVID-19, caused by SARS-CoV-2, is still a global public health concern due to the absence of effective antiviral treatment against different strains. Studies have shown that pregnant women are more susceptible to COVID-19 due to altered physiology and immunological features. Therefore, this study was designed to investigate pregnant women's knowledge, attitudes, and practice (KAP) to prevent COVID-19 and determine the factors associated with KAP. Methods: A community-based cross-sectional study was conducted among 425 pregnant women in Northern Bangladesh. The samples were obtained using a simple random sampling technique from April 5 to June 15, 2020. The data were collected by face-to-face survey with a structured and pre-tested questionnaire and analyzed using SPSS version 25. Bivariable and multivariable logistic regression analyses were performed, and p-values < 0.05 at 95% CI were considered statistically significant. Results: Overall, the score of KAP among the respondents was 47.76%, 49.41%, and 56.24%, respectively. Participants' area of residence, educational status of the husband, and antenatal care (ANC) visit were significantly associated with the level of knowledge, whereas age, educational status of the husband, number of living children, and knowledge were significant predictors of attitude. The knowledge of COVID-19 was the only predictor associated with the practice. Conclusion: Our study shows that almost half of the participants had poor knowledge, a negative attitude, and poor practices toward COVID-19. Additional health education programs by healthcare professionals and different media, coordinated and combined efforts of government and individuals' participation will be required to fight the spread of the infection.

COVID-19 vaccine hesitancy and its enablers would shape community uptake of non-covid vaccines such as oral cholera vaccine (OCV) in the post-COVID-19 era. This study assessed the impact of COVID-19 vaccine hesitancy and its drivers on OCV hesitancy in a cholera endemic region of the Democratic Republic of Congo. We conducted a community-based survey in Bukavu. The survey included characteristics, intention to take OCV and COVID-19, reasons for COVID-19 hesitancy, and thinking and feeling about COVID-19 vaccines. Poisson regression analyses were performed. Of the 1708 respondents, 84.66% and 77.57% were hesitant to OCV alone and to both OCV and COVID-19, respectively. Hesitancy to COVID-19 vaccines rose OCV hesitancy by 12% (crude Prevalence Ratio, [cPR]=1.12, 95%CI[1.03-1.21]). Independent predictors of OCV hesitancy were living in semi-urban area (adjusted Prevalence Ratio [aPR]=1.10, 95%CI[1.03-1.12]), religious refusal of vaccines (aPR=1.06, 95%CI[1.02-1.12]), concerns about vaccine safety (aPR=1.05, 95%CI[1.01-1.11]) and adverse effects (aPR=1.06, 95%CI[1.01-1.12]), as well as poor knowledge (aPR=1.07, 95%CI[1.01-1.14]). Conversely, the belief about COVID-19 vaccine effectiveness reduced OCV hesitancy (aPR=0.76, 95%CI[0.62-0.93]). COVID-19 vaccine hesitancy and its drivers exhibiting a significant domino effect on OCV uptake. Addressing vaccine hesitancy through community-based health literacy interventions would likely improve the introduction of novel non-COVID-19 vaccines in post-COVID-19 era.

Coronavirus disease 2019 (COVID-19), the global pandemic caused by severe acute respiratory syndrome 2 virus (SARS-CoV-2) infection, has caused millions of infections and fatalities worldwide. Extensive SARS-CoV-2 research has been conducted to develop therapeutic drugs and prophylactic vaccines, and even though some drugs have been approved to treat SARS-CoV-2 infection, treatment efficacy remains limited. Therefore, preventive vaccination has been implemented on a global scale and represents the primary approach to combat the COVID-19 pandemic. Approved vaccines vary in composition, although vaccine design has been based on either the key viral structural (spike) protein or viral components carrying this protein. Therefore, mutations of the virus, particularly mutations in the S protein, severely compromise effectiveness of current vaccines and the ability to control COVID-19 infection. This review begins by describing the SARS-CoV-2 viral composition, mechanism of infection, role of angiotensin-converting enzyme 2, host defense responses against infection and the most common vaccine designs. Next, this review summarizes the common mutations of SARS-CoV-2 and how these mutations change viral properties, confer immune escape and influence vaccine efficacy. Finally, this review discusses global strategies that have been employed to mitigate the decreases in vaccine efficacy encountered against new variants.

The newly emerged variants of SARS-CoV-2 created a potential threat among societies and highlighted one of the significant concerns in facing the pandemic. SARS-CoV-2 variants harboring mutations in the structural protein, especially in the RBD domain of spike protein, have raised concern about potential immune escape. The spike protein of SARS-CoV-2 play a vital role in infection and is an important target for neutralizing antibodies. The mutations that occur in the structural proteins, especially in the spike protein, lead to changes in the virus attributes of transmissibility, an increase in disease severity, a notable reduction in neutralizing antibodies generated, and thus a decreased response to vaccines and therapy. The immune response against SARS-CoV-2 has been reported mainly through innate immune responses rather than adaptive immune responses. SARS-CoV-2 invades the host's innate immunity, possibly through inducing cytokine storm, impairing type I IFN responses, and suppressing antigens presentation to T cells. Therefore, the adaptive immune response is required to combat SARS-CoV-2 infection. The SARS-CoV-2 infections activated both arms of adaptive immunity; humoral and cell-mediated immunity. The observed multiple mutations in the RBD domain of the spike protein compromised the adaptive immune response and showed immune escape because it increases the affinity of spike protein binding with the ACE-2 receptor of host cells and increases resistance to neutralizing antibodies. Cytotoxic T-cell responses are crucial in controlling SARS-CoV-2 infections from the infected tissues and clearing them from circulation. CD8+cytotoxic T cells identify and directly kill the infected cells by releasing soluble mediators perforin and granzymes. The functional exhaustion of cytotoxic T cells may increase the severity of the disease. The expression of activation markers of T cells could indicate hyperactivation or functional exhaustion; the exact implication is not yet understood in SARS-CoV-2 infections. These mutations at critical residues influence the antigenic profile of SARS-CoV-2, which may evade the immune responses and thus reduce the immunogenicity and efficacy of vaccines. Therefore, the spike protein may be recognized as a primary target for vaccines and drugs. This review article summarizes the impact of mutations in the spike protein of SARS-CoV-2, especially mutations of RBD, on immunogenicity, immune escape, and vaccine-induced immunity, which could potentially contribute to future studies focusing on vaccine design and immunotherapy.