Efficacy and Safety of COVID-19 Vaccines: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Evolution of microneedle applicators for vaccination: the role of the latch applicator in optimizing dissolving microneedle-based immunization

INTRODUCTION

Dissolving microneedles (DMN) offer advantages in vaccine delivery, such as enhanced immunogenicity and simplified administration, by targeting immune-rich layers of the skin. However, these benefits require precise and consistent delivery, which poses practical challenges. To address this, specialized applicators are essential for ensuring the accurate deployment of DMNs, making this technology a viable alternative to traditional methods, particularly in low- and middle-income countries (LMICs), where healthcare infrastructure is limited.

AREAS COVERED

In this review, we examine the advancements in DMN-based vaccination and applicator design, focusing on their joint effort. These innovations have improved the precision and efficiency of DMN vaccine delivery. Complex and costly early-stage applicators have evolved into simpler and more cost-effective designs. We highlight these developments in this review, with the latch applicator as a key example of a feature that enhances vaccine delivery.

EXPERT OPINION

Although applicator development has advanced DMN-based vaccination toward practical use, challenges remain. Key areas for further optimization include user friendliness, cost, packaging volume, and wear time. Once optimized, DMN vaccination may become a highly effective and accessible tool for global immunization, supporting efforts to achieve worldwide vaccine equality.

Rhabdomyolysis secondary to COVID-19 infection and vaccination: a review of literature

Rhabdomyolysis (RML), characterized by the breakdown of skeletal muscle fibers and the release of muscle contents into the bloodstream, has emerged as a notable complication associated with Coronavirus disease 2019 (COVID-19) infection and vaccination. Studies have reported an increased incidence of RML in individuals with severe COVID-19 infection. However, the exact mechanisms remain unclear and are believed to involve the host's immune response to the virus. Furthermore, RML has been documented as a rare adverse event following COVID-19 vaccination, particularly with mRNA vaccines. Proposed mechanisms include immune responses triggered by the vaccine and T-cell activation against viral spike proteins. This study aims to review the current literature on the incidence, pathophysiology, clinical presentation, and outcomes of RML secondary to COVID-19 infection and vaccination. We identify common risk factors and mechanisms underlying this condition by analyzing case reports, clinical studies, and pharmacovigilance data. Our findings suggest that while RML is a relatively rare adverse event, it warrants attention due to its potential severity and the widespread prevalence of COVID-19 and its vaccines. This review underscores the need for heightened clinical awareness and further research to optimize management strategies and improve patient outcomes in this context.

COVID-19 vaccines: current and future challenges

As of December 2020, around 200 vaccine candidates for Coronavirus Disease 2019 (COVID-19) are being developed. COVID-19 vaccines have been created on a number of platforms and are still being developed. Nucleic acid (DNA, RNA) vaccines, viral vector vaccines, inactivated vaccines, protein subunit vaccines, and live attenuated vaccines are among the COVID-19 vaccine modalities. At this time, at least 52 candidate vaccines are being studied. Spike protein is the primary protein that COVID-19 vaccines are targeting. Therefore, it is critical to determine whether immunizations provide complete or fractional protection, whether this varies with age, whether vaccinated people are protected from reoccurring diseases, and whether they need booster shots if they've already been inoculated. Despite the enormous achievement of bringing several vaccine candidates to market in less than a year, acquiring herd immunity at the national level and much more so at the global level remains a major challenge. Therefore, we gathered information on the mechanism of action of presently available COVID-19 vaccines in this review and essential data on the vaccines' advantages and downsides and their future possibilities.

COVID 19: Prevention and treatment through the Indian perspective

The most destructive period the world has experienced seems to be behind us. Not a single nation was spared by this disease, and many continue to struggle today. Even after recovering from COVID, patient may continue to experience some post-COVID effects, such as heart irregularities or a decline in lung vitality. In the past three years (2019-2022), the world has witnessed the power of a small entity, a single peculiar virus. Science initially appeared to be helpless in this regard, but due to the emergence of disease, pharmaceutics (the development of anti-covid drugs), immunology (the rapid antigen test), microbiology (the isolation of viruses from infected people), biotechnology (the development of recombinant vaccines), biochemistry (the blood profile, the D-dimer test), and biochemistry (blood profile, D-dimer test), biophysics (PCR, RT-PCR, CT Scan, MRI) had worked together to fight the disease. The results of these efforts are the development of new diagnostic techniques, possible treatment and finally the availability of vaccines against COVID-19. However, it is not proven that the treatment through the traditional medical system is directly active on SARS-CoV-2 but is instead indirectly acting on SARS-CoV-2 effects by improving symptoms derived from the viral disease. In India, the traditional system of medicine and tradition knowledge together worked in the pandemic and proved effective strategies in prevention and treatment of SARS-CoV-2. The use of effective masks, PPE kits, plasma therapy, yoga, lockdowns and social seclusion, use of modern antiviral drugs, monoclonal antibodies, herbal remedies, homoeopathy, hygienic practice, as well as the willpower of people, are all contributing to the fight against COVID. Which methods or practices will be effective against COVID nobody is aware since medical professionals who wear PPE kits do not live longer, and some people in India who remained unprotected and roamed freely were not susceptible to infection. The focus of this review is on the mode of transmission, diagnosis, preventive measures, vaccines currently under development, modern medicine developed against SARS-CoV-2, ayurvedic medicine used during pandemic, homoeopathic medicine used during pandemic, and specific yoga poses that can be used to lessen COVID-related symptoms.

Feasibility and Effectiveness of Vaccines for COVID-19: An Umbrella Review

Introduction

In January 2020, WHO declared the 2019 Coronavirus Disease (COVID-19) a pandemic. Though COVID-19 vaccines are recommended, ongoing surveillance is crucial due to potential unforeseen events. Evaluation of long-term effectiveness and safety and addressing emerging variants are vital. This study integrates systematic reviews to assess COVID-19 vaccine efficacy, immunogenicity, and safety comprehensively.

Methods

This study was an umbrella review study on the feasibility and effectiveness of vaccines for COVID-19. We conducted a comprehensive search in PubMed, Web of Sciences, and Scopus, using MeSH terms and keywords related to COVID-19 vaccines. Inclusion criteria comprised peer-reviewed systematic reviews and meta-analyses in English, focusing on feasibility and effectiveness. Exclusion criteria targeted non-systematic reviews exclusively on vaccine safety and duplicates. Two independent reviewers screened and resolved discrepancies. Data extraction included key details. Methodological quality was assessed using the ROBIS tool. Data synthesis involves narrative and, if applicable, quantitative synthesis (meta-analysis). Reporting followed PRISMA guidelines.

Results

A total of 32 systematic reviews were included in the study, of which 20 also conducted a meta-analysis. The studies investigated in the included reviews ranged from 7 to 74. The included articles were conducted in various countries around the globe. The findings indicated that COVID-19 vaccines are generally safe and effective for individuals with various medical conditions. The overall risk of bias for the included studies was assessed as low risk.

Conclusion

The study outcomes indicated that mRNA vaccines exhibit a higher incidence of adverse events but demonstrate greater efficacy. Conversely, inactivated and protein subunit vaccines are safer but exhibit lower efficiency. Moreover, the vaccine is considered safe for individuals with specific conditions such as inflammatory bowel disease, solid organ transplant recipients, children, pregnant individuals, and those with hematologic problems. Ultimately, the acceptance of the COVID-19 vaccine among individuals is influenced by various factors, including geographic, socioeconomic, and pandemic-related considerations.

Convalescent Plasma and Other Antibody Therapies for Infectious Diseases-Lessons Learned from COVID-19 and Future Prospects

Antiviral passive antibody therapy includes convalescent plasma, hyperimmune globulin, and monoclonal antibodies. Passive antibodies have proven effective in reducing morbidity and mortality for SARS-CoV-2 and other infectious diseases when given early in the disease course with sufficiently high specific total and neutralizing antibody levels. Convalescent plasma can be delivered to patients before vaccination implementation or novel drug production. Carefully designed and executed randomized controlled trials near the pandemic outset are important for regulatory bodies, healthcare workers, guideline committees, the public, and the government. Unfortunately, many otherwise well-designed antibody-based clinical trials in COVID-19 were futile, either because they intervened too late in the disease or provided plasma with insufficient antibodies. The need for early treatment mandates outpatient clinical trials in parallel with inpatient trials. Early outpatient COVID-19 convalescent plasma transfusion with high antibody content within 9 days of symptom onset has proven effective in blunting disease progression and reducing hospitalization, thus reducing hospital overcrowding in a pandemic. Convalescent plasma offers the opportunity for hope by enabling community participation in outpatient curative therapy while monoclonal therapies, vaccines, and drugs are being developed. Maintaining the appropriate infrastructure for antibody infusion in both outpatient and inpatient facilities is critical for future pandemic readiness.

Alopecia areata following COVID-19 vaccine: a systematic review

BACKGROUND

To date, multiple cases of adverse reactions to COVID-19 vaccines have been reported worldwide. Alopecia areata (AA) is an uncommon type of adverse reaction reported in some articles and has a significant social and psychological impact on patients. Our study aimed to review the AA and COVID-19 vaccine literature.

METHODS

This systematic review was conducted by searching for articles on AA following COVID-19 vaccines in international databases such as Embase, MEDLINE, PubMed, Web of Knowledge, and Ovid from December 2019 to December 30, 2023. We included studies that provided data for AA patients following COVID-19 vaccination with at least one dose. Data on sex, age, country/region of origin, vaccine type, days between vaccination and symptom presentation, manifestations of AA, trichoscopy and histopathological findings, treatment, and outcomes were included.

RESULTS

In total, 579 explored studies were identified and assessed, and 25 articles with a total of 51 patients were included in the review. Twenty-seven (52.9%) patients developed new-onset AA following receiving the COVID-19 vaccine, and AA recurrence or exacerbation occurred after receiving the COVID-19 vaccine in 24 (47.1%) patients with preexisting disease. Five vaccines were reported to cause AA in all cases. The Pfizer vaccine (45.1%) was the most frequently reported, followed by the ChAdOx1 nCoV-19 vaccine (27.5%), Moderna mRNA-1273 (19.6%), Sinopharm (3.9%) and SinoVac (3.9%). AA occurred most frequently within one month after the 1st dose, and then, the incidence decreased gradually with time. Topical or systemic corticosteroids were used in 38 patients. Eleven patients were treated with a Janus Kinase inhibitor (jakinib) inhibitor, eight with tofacitinib, and three with an unspecified jakinib. However, 3 of the 11 patients experienced exacerbations after treatment.

CONCLUSION

AA after COVID-19 vaccination is rare, and physicians should be aware of this phenomenon to improve early diagnosis and appropriate treatment.

Type 1 diabetes mellitus following COVID-19 vaccination: a report of two cases and review of literature

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) infection, which led to the coronavirus 2019 (COVID-19) pandemic, has promoted the development of novel therapeutic agents and vaccines to combat the global spread of the virus. While the COVID-19 vaccines approved thus far have proven to be effective in clinical settings, there have been reports of autoimmune diseases occurring following vaccination, including autoimmune/inflammatory syndrome induced by adjuvant syndrome. We herein report two cases of type 1 diabetes mellitus that occurred following COVID-19 vaccination and provide a literature review. Both cases received multiple vaccinations as recommended to ensure optimal antibody titers. Moreover, the HLA associated with susceptibility to type 1 diabetes was prototypic in both cases. This indirect evidence suggests that the COVID-19 vaccines may be implicated in the pathogenesis of type 1 diabetes. Further case reports to establish a clearer understanding of a potential association are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-024-00695-9.

New variants of COVID-19 (XBB.1.5 and XBB.1.16, the "Arcturus"): A review of highly questioned concerns, a brief comparison between different peaks in the COVID-19 pandemic, with a focused systematic review on expert recommendations for prevention, vaccination, and treatment measures in the general population and at-risk groups

INTRODUCTION

The COVID-19 pandemic has taken many forms and continues to evolve, now around the Omicron wave, raising concerns over the globe. With COVID-19 being declared no longer a "public health emergency of international concern (PHEIC)," the COVID pandemic is still far from over, as new Omicron subvariants of interest and concern have risen since January of 2023. Mainly with the XBB.1.5 and XBB.1.16 subvariants, the pandemic is still very much "alive" and "breathing."

METHODS

This review consists of five highly concerning questions about the current state of the COVID Omicron peak. We searched four main online databases to answer the first four questions. For the last one, we performed a systematic review of the literature, with keywords "Omicron," "Guidelines," and "Recommendations."

RESULTS

A total of 31 articles were included. The main symptoms of the current Omicron wave include a characteristically high fever, coughing, conjunctivitis (with itching eyes), sore throat, runny nose, congestion, fatigue, body ache, and headache. The median incubation period of the symptoms is shorter than the previous peaks. Vaccination against COVID can still be considered effective for the new subvariants.

CONCLUSION

Guidelines recommend continuation of personal protective measures, third and fourth dose boosters, along with administration of bivalent messenger RNA vaccine boosters. The consensus antiviral treatment is combination therapy using Nirmatrelvir and Ritonavir, and the consensus for pre-exposure prophylaxis is Tixagevimab and Cilgavimab combination. We hope the present paper raises awareness for the continuing presence of COVID and ways to lower the risks, especially for at-risk groups.

Effectiveness of different booster vaccine combinations against SARS-CoV-2 during a six-month follow-up in Mexico and Argentina

Introduction

Given the limited number of patients in Latin America who have received a booster dose against the COVID-19, it remains crucial to comprehend the effectiveness of different vaccine combinations as boosters in real-world scenarios. This study aimed to assess the real-life efficacy of seven different vaccine schemes against COVID-19, including BNT162b2, ChAdOx1-S, Gam-COVID-Vac, and CoronaVac as primary schemes with either BNT162b2 or ChAdOx1-S as booster vaccines.

Methods

In this multicentric longitudinal observational study, participants from Mexico and Argentina were followed for infection and SARS-CoV-2 Spike 1-2 IgG antibodies during their primary vaccination course and for 185 days after the booster dose.

Results

A total of 491 patients were included, and the booster dose led to an overall increase in the humoral response for all groups. Patients who received BNT162b2 exhibited the highest antibody levels after the third dose, while those with primary Gam-COVID-Vac maintained a higher level of antibodies after six months. Infection both before vaccination and after the booster dose, and Gam-COVIDVac + BNT162b2 combination correlated with higher antibody titers.

Discussion

The sole predictor of infection in the six-month follow-up was a prior COVID-19 infection before the vaccination scheme, which decreased the risk of infection, and all booster vaccine combinations conveyed the same amount of protection.

Herpesviral Keratitis Following COVID-19 Vaccination: Analysis of NHIS Database in Korea

PURPOSE

The purpose of this study was to determine the risk of herpesviral keratitis associated with 4 coronavirus disease 2019 (COVID-19) vaccines approved in South Korea, using large-scale data from the National Health Insurance Service.

METHODS

The study included 8,528,254 individuals, with cohorts categorized based on COVID-19 vaccination status. Two investigations were conducted: The first aimed to assess the risk of new-onset herpesviral keratitis while the second study focused on the risk of relapse in individuals with a preexisting diagnosis. Propensity score matching was used for cohort balancing, and various covariates, including vaccine types and comorbidities, were considered. Statistical analyses, including Cox proportional hazard regression, were used to calculate adjusted hazard ratio (aHR) and assess the risk of herpesviral keratitis.

RESULTS

Individuals receiving COVID-19 vaccination exhibited a higher risk of new-onset herpesviral keratitis compared with the unvaccinated control group (aHR 1.43, 95% confidence interval, 1.19-1.73). Both mRNA and non-mRNA vaccines demonstrated an increased risk. Individuals with preexisting herpetic keratitis who received COVID-19 vaccination showed a higher risk of relapse herpesviral keratitis compared with the unvaccinated control group (aHR 1.98, 95% CI, 1.29-3.03). Sensitivity analyses supported the robustness of the results.

CONCLUSIONS

This analysis of a large national health insurance database suggests an increased risk of both new-onset and relapse of herpesviral keratitis associated with COVID-19 vaccination in South Korea. While COVID-19 vaccination is crucial for pandemic control, health care providers should be aware of potential herpesvirus reactivation and consider appropriate prophylaxis and treatment for at-risk individuals.

Immunogenicity, Effectiveness, and Safety of COVID-19 Vaccines among Patients with Immune-Mediated Dermatological Diseases: A Systematic Review and Meta-analysis

Immunocompromised individuals, primarily attributable to using immunosuppressants, face heightened COVID-19 risks. Despite the proven efficacy of COVID-19 vaccines, their impact on patients with immune-mediated dermatological diseases remains unclear. This study aims to thoroughly examine vaccine immunogenicity, effectiveness, and safety in immune-mediated dermatological disease patients. Clinical studies in adults that compared vaccinated immune-mediated dermatological disease patients with vaccinated healthy controls or unvaccinated immune-mediated dermatological disease patients in terms of vaccine immunogenicity, COVID-19 infection, adverse events, or exacerbation of immune-mediated dermatological diseases were searched via electronic databases. Seventeen studies (1,348,690 participants) were included. Seroconversion rates between immune-mediated dermatological disease patients and healthy controls were not different. However, among individuals aged ≤55 years, immune-mediated dermatological disease patients had lower mean anti-SARS-CoV-2 IgG levels. Immunosuppressed immune-mediated dermatological disease patients also had lower titres and were less likely to achieve T-cell response. In terms of safety, the risk of adverse events was higher in atopic dermatitis patients, but those with psoriasis had a reduced risk. Additionally, immunosuppressed patients had fewer adverse events. Vaccinated immune-mediated dermatological disease patients had a lower risk of COVID-19 infection than unvaccinated patients but a higher risk than healthy controls; however, disease exacerbation may be induced. In conclusion, immune-mediated dermatological diseases showed a reduced vaccine response in our meta-analysis, yet vaccination remained effective against COVID-19 infection and well tolerated.

Vaccine adjuvants: current status, research and development, licensing, and future opportunities

Vaccines represent one of the most significant inventions in human history and have revolutionized global health. Generally, a vaccine functions by triggering the innate immune response and stimulating antigen-presenting cells, leading to a defensive adaptive immune response against a specific pathogen's antigen. As a key element, adjuvants are chemical materials often employed as additives to increase a vaccine's efficacy and immunogenicity. For over 90 years, adjuvants have been essential components in many human vaccines, improving their efficacy by enhancing, modulating, and prolonging the immune response. Here, we provide a timely and comprehensive review of the historical development and the current status of adjuvants, covering their classification, mechanisms of action, and roles in different vaccines. Additionally, we perform systematic analysis of the current licensing processes and highlights notable examples from clinical trials involving vaccine adjuvants. Looking ahead, we anticipate future trends in the field, including the development of new adjuvant formulations, the creation of innovative adjuvants, and their integration into the broader scope of systems vaccinology and vaccine delivery. The article posits that a deeper understanding of biochemistry, materials science, and vaccine immunology is crucial for advancing vaccine technology. Such advancements are expected to lead to the future development of more effective vaccines, capable of combating emerging infectious diseases and enhancing public health.

Understanding the time-driven shifts of vaccine effectiveness against any and severe COVID-19 before and after the surge of Omicron variants within 2.5 years of vaccination: A meta-regression

OBJECTIVES

The COVID-19 pandemic required rapid development of vaccines within a short period of time which did not allow to assess vaccine effectiveness (VE) in the long-term.

METHODS

A computerized literature search was undertaken to identify eligible studies, with no language restrictions, published between 1 December 2020 and 30 June 2023.

RESULTS

Out of a total of 27,597 publications, 761 studies were included. Early VE of 87.2% decreased to 55.1% after 9 months among populations fully immunized not only with mRNA (proxy mRNA) vaccines, and 66.3% decreased to 23.5% in populations immunized exclusively with non-mRNA vaccines. Protection against severe COVID-19 declined to 80.9% for proxy mRNA vaccines and 67.2% for non-mRNA vaccines. Omicron variants significantly diminished VE. Within 6-8 months of receiving a single booster of an mRNA vaccine, VE declined to 14.0% and 67.7% for any and severe COVID-19, respectively. Multiple mRNA booster doses restored protection that declined to 29.5% and 70.6% for any and severe COVID-19, respectively, within 5-7 months.

CONCLUSION

Outcomes of this meta-regression underscore the evolving nature of COVID-19 in response to vaccination, dosing schedules, and emerging variants, and provide crucial insights for public health interventions and vaccination strategies.

Understanding and mitigating negative affect in preventive health behaviors: Evidence from the COVID-19 vaccination process

The study investigated the willingness for vaccine uptake during the COVID-19 pandemic (April-June 2021), and explored the effect of both mindfulness and health education in managing negative affect post-vaccination. In study 1, a sample of 468 Chinese college students completed a one-time survey, assessing loneliness, stress, medical fear, and vaccination likelihood. Results showed that medical fear mediated the relationship between loneliness, stress and vaccination likelihood. In study 2, 70 college students were randomly assigned to one of three intervention conditions (mindfulness, health education, and control) during vaccination. Participants in mindfulness group showed lower negative affect scores than the control group post-intervention (p = 0.019). However, no significant difference was reported between health education with the other two conditions. As such, medical fear would be an important factor to target for improving the likelihood of vaccine uptake. Furthermore, a short mindfulness intervention was effective to improve experience of vaccination through mitigating negative affect.

COVID-19 vaccines breakthrough infection and adverse reactions in medical students: a nationwide survey in Iran

Introduction

There are different types of COVID-19 vaccines approved worldwide. Since no national studies focus on vaccine-related adverse reactions and breakthrough cases, this study aimed to investigate the rate of adverse events and COVID-19 infection in medical students in Iran.

Methods

This retrospective cohort study included Iranian medical students who received two doses of COVID-19 vaccines. The medical team gathered the demographic characteristics, comorbidities, type of vaccine, adverse events following vaccination, and history of COVID-19 infection data through a phone interview. The frequency of adverse events and breakthrough infection was stratified by vaccine type (ChAdOx1-S, Gam-COVID-Vac, and BIBP-CorV).

Results

A total of 3,591 medical students enrolled in this study, of which 57.02% were females, with a mean age of 23.31 + 4.87. A PCR-confirmed and suspicious-for-COVID-19 breakthrough infection rate of 4.51 and 7.02% was detected, respectively. There was no significant relation between breakthrough infection and gender, BMI, blood groups, and comorbidities. However, there was a significant difference in breakthrough infection rate among different types of vaccines (p = 0.001) and history of COVID-19 infection (p = 0.001). A total of 16 participants were hospitalized due to COVID-19 infection after vaccination for reasons such as dyspnea, abnormal imaging, or decreased oxygen saturation. No severe infection or death was observed in the studied population.

Conclusion

Vaccination prevented severe COVID-19 infection, although a high breakthrough infection rate was evident among Iranian medical students during the Delta variant's peak. Vaccine effectiveness may be fragile during emerging new variants and in high-exposure settings. Moreover, adverse events are rare, and the benefits of vaccination outweigh the side effects. However, many limitations challenged this study, and the results should be cautious.

Immunogenicity and safety of heterologous booster with protein-based COVID-19 vaccine (NVX-CoV2373) in healthy adults: A comparative analysis with mRNA vaccines

BACKGROUND

Information on the protein-based severe acute respiratory syndrome (SARS-CoV-2) vaccine-NVX-CoV2373 (Novavax), as a heterologous booster remains limited. We investigated the immunogenicity and adverse events of NVX-CoV2373 as a second booster and compared them with those of mRNA vaccines in healthy adults.

METHODS

Healthcare workers who had received an mRNA vaccine (mRNA-1273 or BNT-162b2) as the first booster (third dose) 12 weeks prior were recruited. Participants voluntarily received either NVX-CoV2373 or an mRNA vaccine as a second booster. Participants with a history of SARS-CoV-2 infection were excluded. The primary outcomes included serum anti-SARS-CoV-2 spike protein (SP) and neutralizing antibody titers against B.1.1.7 (Alpha), B.1.1.529 (Omicron) BA2, and BA5 variants on the 28th day after the boost. Secondary outcomes included new SARS-CoV-2 infections and adverse events reported during the study period.

RESULTS

A total of 160 participants were enrolled in this study. Compared with the mRNA vaccination group (n = 59), the NVX-CoV2373 vaccination group (n = 101) had significantly lower anti-SARS-CoV-2 SP antibody titers and neutralizing antibody titers against all variants tested after the boost. During the study period, higher rates of new SARS-CoV-2 infections and a lower incidence of adverse events were observed in the NVX-CoV2373 vaccination group. No significant differences in cellular immune responses were observed between the two groups.

CONCLUSION

Compared to a homologous mRNA booster vaccination, heterologous boosters with NVX-CoV2373 showed lower antibody responses, a higher incidence of new SARS-CoV-2 infections, and fewer adverse events.

Comparative efficacy and safety of COVID-19 vaccines in phase III trials: a network meta-analysis

BACKGROUND

Over a dozen vaccines are in or have completed phase III trials at an unprecedented speed since the World Health Organization (WHO) declared COVID-19 a pandemic. In this review, we aimed to compare and rank these vaccines indirectly in terms of efficacy and safety using a network meta-analysis.

METHODS

We searched Embase, MEDLINE, and the Cochrane Library for phase III randomized controlled trials (RCTs) from their inception to September 30, 2023. Two investigators independently selected articles, extracted data, and assessed the risk of bias. Outcomes included efficacy in preventing symptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the incidence of serious adverse events (SAEs) according to vaccine type and individual vaccines in adults and elderly individuals. The risk ratio and mean differences were calculated with 95% confidence intervals using a Bayesian network meta-analysis.

RESULTS

A total of 25 RCTs involving 22 vaccines were included in the study. None of vaccines had a higher incidence of SAEs than the placebo. Inactivated virus vaccines might be the safest, with a surface under the cumulative ranking curve (SUCRA) value of 0.16. BIV1-CovIran showed the highest safety index (SUCRA value: 0.13), followed by BBV152, Soberana, Gam-COVID-Vac, and ZF2001. There were no significant differences among the various types of vaccines regarding the efficacy in preventing symptomatic SARS-CoV-2 infection, although there was a trend toward higher efficacy of the mRNA vaccines (SUCRA value: 0.09). BNT162b2 showed the highest efficacy (SUCRA value: 0.02) among the individual vaccines, followed by mRNA-1273, Abdala, Gam-COVID-Vac, and NVX-CoV2373. BNT162b2 had the highest efficacy (SUCRA value: 0.08) in the elderly population, whereas CVnCoV, CoVLP + AS03, and CoronaVac were not significantly different from the placebo.

CONCLUSIONS

None of the different types of vaccines were significantly superior in terms of efficacy, while mRNA vaccines were significantly inferior in safety to other types. BNT162b2 had the highest efficacy in preventing symptomatic SARS-CoV-2 infection in adults and the elderly, whereas BIV1-CovIran had the lowest incidence of SAEs in adults.

[Response to the COVID-19 Health Crisis from a Gender Perspective: Lessons Learned]

OBJECTIVE

To delve deeper from a gender perspective into the lessons learned during the COVID-19 pandemic to address future health crises.

METHOD

Study with key informants with experience in public health and gender from the Ministerio de Sanidad, ministries of the autonomous communities, Institut Català de la Salut, Hospital de La Princesa, Escuela Andaluza de Salud Pública and Universidad País Vasco.

SOURCE OF INFORMATION

individual open-ended questionnaire on health and health inequalities/gender inequalities related to COVID-19. After presenting the findings, the key informants group discussed them in a meeting until reaching a consensus on the lessons learned.

RESULTS

The lack of clinical statistics by sex could compromise epidemiological surveillance, losing the opportunity to characterize the disease. The performance of essential services fell more on women, exhausting them with double and triple shifts; with the differences according to sex in the clinical presentation of COVID-19, and the criteria for hospitalization/admission to the intensive care unit, their access to health care decreased. Increased: gender violence and mental health problems; delaying recognition of the second effects of vaccines in women; partially due to information biases in clinical trials. The gender perspective was lacking in academic, healthcare, and health management areas.

CONCLUSIONS

Women's gender dimensions determined their higher frequency of COVID-19 and played a fundamental role in its control. Broadly considering the lessons learned will strengthen prevention systems and be able to provide effective responses to future health crises.

To be remembered: B cell memory response against SARS-CoV-2 and its variants in vaccinated and unvaccinated individuals

COVID-19 disease has plagued the world economy and affected the overall well-being and life of most of the people. Natural infection as well as vaccination leads to the development of an immune response against the pathogen. This involves the production of antibodies, which can neutralize the virus during future challenges. In addition, the development of cellular immune memory with memory B and T cells provides long-lasting protection. The longevity of the immune response has been a subject of intensive research in this field. The extent of immunity conferred by different forms of vaccination or natural infections remained debatable for long. Hence, understanding the effectiveness of these responses among different groups of people can assist government organizations in making informed policy decisions. In this article, based on the publicly available data, we have reviewed the memory response generated by some of the vaccines against SARS-CoV-2 and its variants, particularly B cell memory in different groups of individuals.

SARS-CoV-2 vaccination and semen quality: a study based on sperm donor candidate data in southwest China

Background

The coronavirus disease 2019 (COVID-19) pandemic has been a global health crisis and continues to pose risk to population health at the present. Vaccination against this disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has become a public health priority worldwide. Yet, limited information is available on the potential impact of such vaccines on human fertility.

Methods

To examine the relationship between COVID-19 vaccination and male fertility, we conducted an observational study on sperm donor candidates in China who received Chinese COVID-19 vaccines between January 1, 2020 to December 31, 2021.

Results

A total of 2,955 semen samples from 564 individuals were assessed along with vaccination information. Statistical analyses were conducted on both the entire study population and the subgroup of individuals who provided repeated semen samples before and after vaccination. While motility related parameters [progressive rate, curvilinear velocity (VCL), average path velocity (VAP), straight-line velocity (VSL), wobble (WOB), straightness (STR), linearity (LIN), amplitude of lateral head displacement (ALH), beat-cross frequency (BCF)] exhibited statistically significant difference before and after vaccination based on Welch two-sample test, mixed effects regression results based on repeated measures from the same individuals indicated that vaccination was not statistically associated with sperm quality parameters except for VCL, VAP, and VSL. Individual variability was the key determinant of sperm quality variance, with contribution ranging from 19% to 82%.

Conclusions

Findings from our study could help to enhance current understanding of male reproductive health in the context of the global pandemic.

Guillain-Barré syndrome post-SARS-CoV-2 vaccine: a systematic review and data analysis on its clinical, laboratory, electrophysiological, and radiological features

Introduction

Guillain-Barré syndrome (GBS) is a rare disease that affects almost 0.8-1.9 cases per 100,000 people worldwide every year. This is the most prevalent cause of subacute flaccid paralyzing illness today. It is a subacute inflammatory demyelinating polyradiculoneuropathy; the typical scenario involves ascending symmetrical flaccid paralysis, but in some circumstances, sensory, autonomic, and cranial neuropathy may also be involved. Several vaccines have been found to have complications since the previous century. Numerous case reports of GBS in the literature have been reported following COVID-19 vaccines in recent times.

Objective

This study aimed to conduct a comprehensive examination of GBS cases that have been reported after COVID-19 vaccines; to analyze the descriptive statistical analysis of data gathered regarding clinical, laboratory, electrophysiological, and radiological characteristics; to discuss, based on the available evidence, whether the disease has a preference for a particular vaccine type; and to speculate on the potential pathogenesis.

Methodology

This review has been carried out by recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Result

Reviewing 60 case reports illustrated that most of them are from the USA (18.1%) and the majority of affected individuals were males (60%). The results favored the association between vector-based SARS-CoV-2 vaccine, particularly AstraZeneca vaccine, and the GBS. The mean of symptoms onset is 11.4 days. The results of diagnostic tests such as LP are consistent mostly with albumin-cytological dissociation (81.81%), where brain and spine MRI was unremarkable in 59.52%. Regarding electrodiagnostic tests, AIDP is the most common variant (61.81%). The management was not consistent among the case reports. However, IVIG is the most frequent way of treating these patients (68.33%). The functional outcome was documented in 47 patients; 65% improved with medical management.

Conclusion

This study aimed to conduct a systematic review of reported cases of GBS following COVID-19 vaccines and descriptive statistical analysis of collected data on clinical, laboratory, electrophysiological, and radiological features, to discuss, based on available results, whether the disease has a predilection to a specific vaccine type and to speculate the potential pathogenesis.

Global landscape of COVID-19 research: a visualization analysis of randomized clinical trials

The emergence of COVID-19 in 2019 has resulted in a significant global health crisis. Consequently, extensive research was published to understand and mitigate the disease. In particular, randomized controlled trials (RCTs) have been considered the benchmark for assessing the efficacy and safety of interventions. Hence, the present study strives to present a comprehensive overview of the global research landscape pertaining to RCTs and COVID-19. A bibliometric analysis was performed using the Scopus database. The search parameters included articles published from 2020 to 2022 using keywords specifically related to COVID-19 and RCTs. The data were analyzed using various bibliometric indicators. The volume of publications, contributions of countries and institutions, funding agencies, active journals, citation analysis, co-occurrence analysis, and future research direction analysis were specifically analyzed. A total of 223,480 research articles concerning COVID-19 were published, with 3,727 of them related to RCTs and COVID-19. The ten most productive countries collectively produced 75.8% of the documents, with the United States leading the way by contributing 31.77%, followed by the UK with 14.03% (n = 523), China with 12.96% (n = 483) and Canada with 7.16% (n = 267). Trials (n = 173, 4.64%), BMJ Open (n = 81, 2.17%), PLOS One (n = 73, 1.96%) and JAMA Network Open (n = 53, 1.42%) were the most active journals in publishing articles related to COVID-19 RCTs. The co-occurrence analysis identified four clusters of research areas: the safety and effectiveness of COVID-19 vaccines, mental health strategies to cope with the impact of the pandemic, the use of monoclonal antibodies to treat patients with COVID-19, and systematic reviews and meta-analyses of COVID-19 research. This paper offers a detailed examination of the global research environment pertaining to RCTs and their use in the context of the COVID-19 pandemic. The comprehensive body of research findings was found to have been generated by the collaborative efforts of multiple countries, institutions, and funding organizations. The predominant research areas encompassed COVID-19 vaccines, strategies for mental health, monoclonal antibodies, and systematic reviews. This information has the potential to aid researchers, policymakers, and funders in discerning areas of weakness and establishing areas of priority.

New diagnosis of multiple sclerosis in the setting of recent Sinopharm COVID-19 vaccine (BBIBP-CorV) exposure: A series of clinical cases and updated review of the literature

Background: Multiple sclerosis (MS) is the most common cause of non-traumatic disability in young individuals. There are limited reports of developing demyelinating events following the coronavirus disease 2019 (COVID-19) vaccination. Methods: We reported all individuals (n = 8) with new MS diagnoses with recent exposure (≤ 6 weeks) to the Sinopharm (BBIBP-CorV) vaccine between September 2021 and June 2022. We also reviewed the related literature published as of September 2023. Results: Of 338 newly diagnosed patients with MS who attended our tertiary referral MS center during the study period, 8 (2.36%) had their first demyelinating attack with a median interval of 2 [2.0, 4.0] weeks following the Sinopharm vaccine (sex ratio 1:1, median age: 20.5 [18.0, 27.0] years). No personal or family history of autoimmune/neurological disorders was documented, except for one patient's history of a previous potential demyelinating event and another's family history of immune thrombocytopenic purpura (ITP). All patients had demyelinating brain MRI lesions, and 4 had cervical spinal cord involvement. The brain areas most commonly affected were the periventricular and subcortical regions. Positive oligoclonal bands (OCBs) in all patients supported the MS diagnosis. All patients were diagnosed with relapsing-remitting MS and received intravenous methylprednisolone (IVMP) alone or in combination with plasma exchange (3/8). Rituximab was the most frequently used disease-modifying treatment (3/8). Conclusion: This study provides preliminary evidence of a potential association between the Sinopharm vaccine and the initial manifestations of MS. However, further larger-scale studies with control groups and long-term follow-ups are needed to confirm this association and determine the underlying mechanisms.

Nonattendance is associated with work performance due to the side effects of COVID-19 vaccination: a cross-sectional study in a Japanese manufacturing industry

OBJECTIVES

Although vaccines have promoted the socioeconomic normalization of COVID-19, adverse effects on work performance due to the post-vaccination side effects have been reported. Thus, we examined the relationship between the status of going to work the day following vaccination as a post-vaccination employment consideration and work performance among Japanese workers in the manufacturing industry.

METHODS

Overall, 1273 employees who received the COVID-19 vaccine in a Japanese manufacturing district were surveyed using a self-administered web-based questionnaire that included fever, fatigue, workplace attendance the day after vaccination, work performance 1 week after vaccination, and demographic and occupational characteristics (age, gender, work style, and psychological distress [K6 scale]). The effects of fatigue and attendance on declining work performance were estimated using a linear mixed model, with individuals as random effects and the rest as fixed effects.

RESULTS

After adjusting for demographic and occupational characteristics, the third-order interaction of fever, fatigue, and attendance on the day following vaccination was significant. The nonattendance group had a significantly higher work performance than the attendance group in those without fever and long-term fatigue (F1,1559 = 4.9, P = .026) and with fever and short-term fatigue (F1,1559 = 5.9, P = .015). Fever and workplace attendance the following day were not directly related to a decrease in work performance after vaccination.

CONCLUSIONS

Our findings suggest that nonattendance at the workplace is associated with work performance due to the side effects after COVID-19 vaccination.

A systematic review and meta-analysis of the global prevalence and determinants of COVID-19 vaccine acceptance and uptake in people living with HIV

People living with HIV (PLHIV) are at higher risk of poor outcomes of SARS-CoV-2 infection. Here we report the pooled prevalence of COVID-19 vaccine acceptance/uptake and determinants among this vulnerable population of PLHIV based on a systematic review and meta-analysis of studies published by 25 August 2023. Among the 54 included studies (N = 167,485 participants), 53 (N = 166,455) provided data on vaccine acceptance rate, while 27 (N = 150,926) provided uptake data. The global prevalences of COVID-19 vaccine acceptance and uptake were 67.0% and 56.6%, respectively. Acceptance and uptake rates were 86.6% and 90.1% for the European Region, 74.9% and 71.6% for the Region of the Americas, 62.3% and 78.9% for the South-East Asian Region, 64.6% and 19.3% for the Eastern Mediterranean Region, 58.0% and 35.5% for the African Region, and 57.4% and 44.0% for the Western Pacific Region. The acceptance rate increased from 65.9% in 2020 to 71.0% in 2022, and the uptake rate increased from 55.9% in 2021 to 58.1% in 2022. Men, PLHIV aged ≥40 years and those who had recently received the influenza vaccine were more likely to accept and receive the COVID-19 vaccine. Factors associated with lower uptake included Black race, other races (Latinx/Hispanic/mixed race), low education level and being unemployed. Vaccine-related factors associated with higher acceptance included belief in vaccine effectiveness, vaccine trust, perceived high susceptibility to SARS-CoV-2 infection and fear of potential COVID-19 effect in PLHIV. Sustained efforts and targeted interventions are needed to reduce regional disparities in COVID-19 vaccine uptake among PLHIV.

Preclinical and Clinical Investigations of Potential Drugs and Vaccines for COVID-19 Therapy: A Comprehensive Review With Recent Update

The COVID-19 pandemic-led worldwide healthcare crisis necessitates prompt societal, ecological, and medical efforts to stop or reduce the rising number of fatalities. Numerous mRNA based vaccines and vaccines for viral vectors have been licensed for use in emergencies which showed 90% to 95% efficacy in preventing SARS-CoV-2 infection. However, safety issues, vaccine reluctance, and skepticism remain major concerns for making mass vaccination a successful approach to treat COVID-19. Hence, alternative therapeutics is needed for eradicating the global burden of COVID-19 from developed and low-resource countries. Repurposing current medications and drug candidates could be a more viable option for treating SARS-CoV-2 as these therapies have previously passed a number of significant checkpoints for drug development and patient care. Besides vaccines, this review focused on the potential usage of alternative therapeutic agents including antiviral, antiparasitic, and antibacterial drugs, protease inhibitors, neuraminidase inhibitors, and monoclonal antibodies that are currently undergoing preclinical and clinical investigations to assess their effectiveness and safety in the treatment of COVID-19. Among the repurposed drugs, remdesivir is considered as the most promising agent, while favipiravir, molnupiravir, paxlovid, and lopinavir/ritonavir exhibited improved therapeutic effects in terms of elimination of viruses. However, the outcomes of treatment with oseltamivir, umifenovir, disulfiram, teicoplanin, and ivermectin were not significant. It is noteworthy that combining multiple drugs as therapy showcases impressive effectiveness in managing individuals with COVID-19. Tocilizumab is presently employed for the treatment of patients who exhibit COVID-19-related pneumonia. Numerous antiviral drugs such as galidesivir, griffithsin, and thapsigargin are under clinical trials which could be promising for treating COVID-19 individuals with severe symptoms. Supportive treatment for patients of COVID-19 may involve the use of corticosteroids, convalescent plasma, stem cells, pooled antibodies, vitamins, and natural substances. This study provides an updated progress in SARS-CoV-2 medications and a crucial guide for inventing novel interventions against COVID-19.

Safety and efficacy of COVID-19 vaccines: A systematic review and meta-analysis of controlled and randomized clinical trials

Vaccines against coronavirus disease 2019 (COVID-19) have been discovered within a very small duration of time as compared to the traditional way for the development of vaccines, which raised the question about the safety and efficacy of the approved vaccines. The purpose of this study is to look at the effectiveness and safety of vaccine platforms against the incidence of COVID-19. The literature search was performed on PubMed/Medline, Cochrane, and clinical trials.gov databases for studies published between 1 January 2020 and 19 February 2022. Preferred Reporting Items for Systemic Review and Meta-Analysis Statement guidelines were followed. Among 284 articles received by keywords, a total of 11 studies were eligible according to the inclusion and exclusion criteria (studies in special populations, e.g., pregnant women, paediatric patients, editorials, case reports, review articles, preclinical and in vitro studies) of the study. A total of 247,186 participants were considered for randomisation at baseline, among them, 129,572 (52.42%) were provided with vaccine (Intervention group) and 117,614 (47.58%) with the placebo (Control group). A pooled fold change estimation of 0.19 (95% CI: 0.12-0.31, p < 0.0001) showed significant protection against the incidence of COVID-19 in the vaccines received group versus the placebo group. mRNA based, inactivated vaccines and non-replicating viral vector-based vaccines showed significantly protection against the incidence of COVID-19 compared to placebo with pooled fold change estimation was 0.08 (95% CI: 0.06-0.10), 0.20 (95% CI: 0.14-0.29) and 0.36 (95% CI: 0.28-0.46), respectively. Injection site discomfort and fatigue were the most common side effect observed in mRNA, non-replicating viral vector, inactivated, and protein subunit-based vaccines. All the approved vaccines were found safe and efficacious but mRNA-based vaccines were found to be more efficacious against SARS-CoV-2 than other platforms.

Herpes Zoster after COVID-19 Infection or Vaccination: A Prospective Cohort Study in a Tertiary Dermatology Clinic

Background

Herpes zoster (HZ) has been observed to occur after COVID-19 infection and vaccination; however, knowledge regarding the demographic data, clinical presentations, and treatment outcomes of HZ is limited.

Objective

To compare the demographic data, clinical manifestations, treatments, and outcomes of patients with and without HZ within 14 days of COVID-19 infection or vaccination.

Methods

This prospective cohort study involving patients diagnosed with cutaneous HZ was conducted at a dermatology clinic from October 2021 to January 2023.

Results

Among a total of 232 patients with HZ, the median age was 62.0 years and 59.1% were female. HZ developed in 23 (9.9%) and four (1.7%) patients after COVID-19 vaccination and infection, respectively. The mean duration from vaccination and the median duration from infection to HZ onset were 5.7 and 8.5 days, respectively. The proportion of female patients was significantly higher in the group of patients with COVID-19 vaccination or infection than in those without such a history (P = 0.035). Patients who developed HZ following the recent COVID-19 infection had a median age of 42.5 years, which was lower than that of the other groups. Dissemination occurred in 8.7% of the patients after COVID-19 vaccination. HZ recurrence was reported in five cases, of which 80% had been vaccinated or infected with COVID-19 during the previous 21 days. All patients had similar durations of antiviral treatment, crust-off time, and duration of neuralgia.

Conclusions

HZ after COVID-19 vaccination is more frequently observed in females, while HZ after COVID-19 infection tends to occur in younger patients. Disseminated HZ is more common in patients recently vaccinated against COVID-19. COVID-19 vaccination or infection may trigger recurrent HZ infection.

Vaccine conspiracy association with higher COVID-19 vaccination side effects and negative attitude towards booster COVID-19, influenza and monkeypox vaccines: A pilot study in Saudi Universities

Conspiracies regarding vaccines are widely prevalent, with negative consequences on health-seeking behaviors. The current study aimed to investigate the possible association between the embrace of vaccine conspiracies and the attitude to booster COVID-19, seasonal influenza, and monkeypox (mpox) vaccinations as well as the perceived side effects following COVID-19 vaccination. The target population involved academic staff and university students in health colleges in the Kingdom of Saudi Arabia. A self-administered questionnaire was distributed in January 2023 to collect data on participants' demographics, self-reported side effects following each dose, willingness to get booster COVID-19, seasonal influenza, and mpox vaccinations, as well as an evaluation of vaccine conspiracies and attitude to mandatory vaccination. Among the 273 participants, the willingness to receive yearly booster COVID-19 vaccination was observed among 26.0% of the participants, while it was 46.9% and 34.1% for seasonal influenza and mpox vaccinations, respectively. Multinomial logistic regression analyses demonstrated a significant correlation between endorsing vaccine conspiracies and higher frequency of self-reported side effects following uptake of the second and third doses of COVID-19 vaccines. Vaccine conspiracies were also correlated with attitude toward booster COVID-19, influenza, mpox, and mandatory vaccination. The findings of this pilot study highlighted the potential adverse impact of the preexisting notions and negative attitudes toward vaccines, which could have contributed to heightened perceived side effects following COVID-19 vaccination. The study also highlighted the ongoing divisions concerning mandatory vaccination policies, emphasizing the need for cautious implementation of this strategy as a last resort for public health benefit.

Investigating mortality trends in Italy during the COVID-19 pandemic: life expectancy changes within provinces and vaccination campaign impact up to December 2022

OBJECTIVES

We used publicly available population data from 1 January 2019 up to 31 December 2022, to investigate mortality trends in Italy during the COVID-19 pandemic, evaluating changes in life expectancy (LE) at birth within provinces and the impact of COVID-19 vaccinations.

STUDY DESIGN

Aggregate data analysis.

METHODS

Annual period life tables were used to estimate sex-specific LEs within provinces from 2019 to 2022. We used Arriaga decomposition to analyze the contribution of age groups (<60 years and ≥60 years) to annual LE changes. We implemented a Quasi-Poisson regression model to estimate the number of averted deaths by the achieved COVID-19 vaccination rates from January 2021 up to December 2022, simulating a counterfactual scenario where vaccine doses were not administered.

RESULTS

The results revealed geographical heterogeneity in annual LE changes across Italian provinces during the pandemic. By the end of 2022, LE was below the prepandemic levels in 88% of provinces for females and in 76% for males. In addition, we estimated that the achieved vaccination rates averted 460,831 deaths (95% confidence interval: 250,976-707,920), corresponding to a 25% reduction in expected all-cause mortality.

CONCLUSIONS

Overall, the study highlighted the significant role of COVID-19 vaccinations in averting a considerable number of deaths and improving LE. However, by the end of 2022, LE had not fully recovered to prepandemic levels in many provinces. This could be attributed to concurrent factors, including enduring COVID-19 pandemic effects, intense summer heat waves and early onset of seasonal flu. Further research and continuous monitoring are essential to fully comprehend long-term mortality trends and optimize public health strategies.

The Relationship Between Menstrual Cycle Irregularities and COVID-19 Vaccination

Background After COVID-19 vaccination, females reported irregularities and changes in their menstrual cycle. We aimed to explore the menstrual irregularities following COVID-19 vaccination in Saudi women of childbearing age. Methodology The study was a cross-sectional study conducted among women in Riyadh, Saudi Arabia, who had no history of menstrual irregularities before receiving the first dose of the COVID-19 vaccine. The participants filled out an online self-administered questionnaire via Google Form about any menstrual irregularities they experienced after receiving the COVID-19 vaccine. Results A total of 535 participants completed the survey. The study found that 41.7% (223) of women experienced menstrual changes after the first dose of the COVID-19 vaccine, increasing to 44.1% (236) after the second dose. The incidence of these changes varied between the first and second doses. For example, the incidence of changes in period duration decreased from 51.6% to 48.3% after the first and second doses, respectively. Similarly, the incidence of delayed periods decreased from 48.4% to 47.9%, while dysmenorrhea increased slightly from 30.9% to 32.2% after the two doses. The incidence of heavier menstrual flow increased from 26.9% to 30.5%, while the incidence of lighter menstrual flow decreased from 26.9% to 24.6% after the first and second doses, respectively. Conclusions There is an increased incidence of changes in menstrual cycle after COVID-19 vaccination, particularly in menstrual cycle length, menstrual pain, and the flow of menstruation. Future studies are needed to investigate the potential underlying biological mechanisms.

Administration of an excessive dosage of covid-19 pfizer vaccine in an infant: Case report of clinical and immune responses

Introduction/Case report

We describe the case of a 6-month-old female infant who received the equivalent of 6 adult doses of the COVID-19 Pfizer vaccine due to an immunization error. The patient underwent clinical and laboratory evaluations from the time of vaccination error (January 2022) until November 2022. In the first three days after immunization, she presented with low-grade fever (38 °C) and mild pain and induration at the injection site. She showed no other symptoms afterwards. Laboratory tests were within normal limits for age, except for an elevated D-dimer (3.71 ug/mL; normal: up to 0.5 ug/mL) and as the echocardiogram and electrocardiogram were within normal limits as well, no interventions were instituted at that moment. On the tenth day, immune response evaluation showed a strong expression of cytokines related to the Th2 profile and a well-controlled inflammatory state. Forty-three days after the vaccine administration inflammation status remained, with a predominance of cellular immune response, IFN-γ expression increased compared to the previous evaluation, and a robust antiviral state was in place. After 90 days, immune response evaluation showed a significant reduction in the inflammatory state, still with a predominance of the cellular immune response. Clinically, the patient remained well, with no other noteworthy intercurrences, until the last appointment in November 2022. This child has had no evidence of a severe adverse effect associated to the vaccine overdose.

Conclusion

The close follow-up of this case of vaccination error demonstrated that the COVID-19 Pfizer was safe and immunogenic in this individual, noting careful monitoring and followup of these vaccine administration errors is crucial.

Unraveling the association between vaccine attitude, vaccine conspiracies and self-reported side effects following COVID-19 vaccination among nurses and physicians in Jordan

Background

The negative impact of vaccine conspiracies is linked with negative health behavior. The aim of the current study was to examine the association between attitudes toward booster COVID-19, influenza, and monkeypox (mpox) vaccinations with post-COVID-19 vaccine side effects, vaccine conspiracies, and attitude towards mandatory vaccination among nurses and physicians in Jordan.

Methods

A structured closed-ended questionnaire was used to collect data on demographics, COVID-19 history, COVID-19 vaccine type and doses received, self-reported side effects post-COVID-19 vaccination, acceptance of booster COVID-19, seasonal influenza, and mpox vaccinations, attitudes towards mandatory vaccination, and beliefs in vaccine conspiracies.

Results

The study sample comprised a total of 341 participants. Acceptance of yearly booster COVID-19 vaccination was expressed by 46.6% of the sample, while 73.3% accepted seasonal influenza vaccination, and only 37.0% accepted mpox vaccination. A higher frequency of self-reported side effects following the first COVID-19 vaccine dose was associated with embrace of vaccine conspiracies and vaccine type. For the second vaccine dose, a higher frequency of self-reported side effects was associated with the embrace of vaccine conspiracies, older age, and affiliation to private sector. In multinomial logistic regression analyses, the lower embrace of vaccine conspiracies was associated with lower odds of reporting side effects post-COVID-19 vaccination. The lower embrace of vaccine conspiracies and favorable attitude towards mandatory vaccination were associated with the willingness to get COVID-19, influenza, and mpox vaccinations.

Conclusion

The study findings highlighted the negative impact of embracing vaccine conspiracies on health-seeking behavior among nurses and physicians. The findings indicated that the willingness to get vaccinated was associated with lower endorsement of vaccine conspiracies. Additionally, the lower embrace of vaccine conspiracies was associated with a lower frequency of self-reported side effects following COVID-19 vaccination. These results emphasize the importance of addressing vaccine misinformation and promoting accurate information to ensure optimal vaccine uptake and public health outcomes.

mRNA vaccine development during the COVID-19 pandemic: a retrospective review from the perspective of the Swiss affiliate of a global biopharmaceutical company

The coronavirus disease 2019 (COVID-19) pandemic has been the defining public health emergency of our time. In Switzerland, messenger RNA (mRNA) vaccines were and still are widely utilized as a critical component of the Federal Office of Public Health (FOPH)'s preventative mitigation strategy. The development, conditional approval and worldwide roll-out of mRNA vaccines against COVID-19 proceeded at an unprecedented pace and presented myriad challenges for manufacturers. In this review, we discuss, from the perspective of the Swiss affiliate of a global biopharmaceutical company, the clinical, regulatory, pharmacovigilance and logistical considerations of making a mRNA COVID-19 vaccine available to the Swiss population during a pandemic as rapidly as possible while ensuring strict adherence to safety and quality standards.

Inflammatory and cytotoxic mediators in COVID-19 patients and in ChAdOx1 nCoV-19 (AZD1222) vaccine recipients

Immunological and cytotoxic mediators are induced in natural infection and are essential for the effectiveness of vaccination. Vaccination is useful to prevent the spread of SARS-CoV-2 and limit the morbidity/mortality of COVID-19. ChAdOx1 nCoV-19 is one of the most widespread vaccines in the world. We compared the detection of anti-S1 SARS-CoV2 IgG and the profile of inflammatory and cytotoxic responses of patients who developed different clinical outcomes of COVID-19 with individuals previously exposed or not to the virus received the first and booster doses of ChAdOx1 nCoV-19. Plasma from 35 patients with COVID-19 and 11 vaccinated were evaluated by multiplex assay. Here, no vaccinated subjects had serious adverse effects. Those vaccinated with a booster dose had higher anti-S1 IgG than mild/moderate and recovered patients. Critically ill and deceased patients had IgG levels like those immunized. By univariate analysis, IL-2, IL-17, and perforin do not differentiate between patients and vaccinated individuals. Granzyme A increased at dose 1, while patients had their levels reduced. High levels of granulysin, sFas, and IL-6 were detected in the deaths, but after vaccination, all were declined. The multivariate analysis supports the role of IL-6 and granulysin as associated and non-confounding variables related to the worst clinical outcome of COVID-19, but not sFas. Our data confirm the ability of the ChAdOx1 vaccine to produce specific antibody levels up to booster time. Furthermore, our data suggest that the vaccine can regulate both the hyper-production and the kinetics of the production of inflammatory and cytotoxic mediators involved in the cytokine storm, such as granulysin and IL-6.

Prevalence of Side Effects of the AstraZeneca COVID-19 Vaccine: A Multicenter Experience From Pakistan

Introduction The most efficient method of combating the coronavirus disease 2019 (COVID-19) pandemic would be to use effective, safe, and proven vaccines; however, their widespread use has been hampered partly by concerns over possible adverse effects. Therefore, this study aimed to assess the prevalence of Oxford/AstraZeneca vaccine side effects among participants. Methods This was a multicenter, cross-sectional study conducted using a non-probability sampling technique. The duration of the study was nine months, from February 1, 2022, to October 31, 2022. The study included 900 participants who provided informed consent and had received two doses of the AstraZeneca vaccine. Demographic characteristics of participants, such as gender, age, comorbidities, AstraZeneca vaccine with both doses along with booster dose, previous exposure to COVID-19 infection, and the prevalence of any local and systemic side effects following the first and second doses of vaccine, were documented. Results The study findings showed that of the 900 participants, 414 (46.0%) were males and 486 (54.0%) were females; their mean age was 40.72 ± 13.47 years. Among them, 198 (22.0%) had hypertension and 144 (16.0%) had diabetes mellitus. Following the first dose of the AstraZeneca vaccine, pain at the injection site was the most commonly reported side effect in 594 (66.0%) participants. Moreover, swelling at the injection site was the most commonly reported side effect in 522 (58.0%) participants after receiving the second dose of the vaccine. The level of satisfaction showed that the majority of the 648 participants (72.0%) were satisfied with their vaccination. Conclusion This study concluded that pain at the injection site was the most commonly reported side effect, followed by swelling and fever after the first dose of the vaccine. Following the second dose of the vaccine, adverse effects included headache, swelling, and burning at the injection site.

Menstrual abnormalities after COVID-19 vaccination in the Netherlands: A description of spontaneous and longitudinal patient-reported data

AIMS

During the COVID-19 vaccination campaigns, the number of reports of menstrual abnormalities increased rapidly. Here, we describe the nature and potential risk factors associated with menstrual abnormalities based on spontaneously reporting data as well as data from a prospective cohort event monitoring (CEM) study as these are poorly studied.

METHODS

Reports of menstrual abnormalities received by the Netherlands Pharmacovigilance Centre Lareb in the spontaneous reporting system between February 2021 and April 2022 were summarized. In addition, logistic regression analysis was performed on the reported menstrual abnormalities in the CEM study to assess the association between person characteristics, prior SARS-CoV-2 infection and use of hormonal contraceptives and the occurrence of menstrual abnormalities after vaccination.

RESULTS

We analysed over 24 000 spontaneous reports of menstrual abnormalities and over 500 episodes (among 16 929 included women) of menstrual abnormalities in the CEM study. The CEM study showed an incidence of 41.4 per 1000 women aged ≤54 years. Amenorrhoea/oligomenorrhoea and heavy menstrual bleeding collectively accounted for about half of all abnormalities reported. Significant associations were observed for the age group 25-34 years (odds ratio 2.18; 95% confidence interval 1.45-3.41) and the Pfizer vaccine (odds ratio 3.04; 95% confidence interval 2.36-3.93). No association was observed for body mass index and presence of most comorbidities assessed.

CONCLUSION

The cohort study showed a high incidence of menstrual disorders among women aged ≤54 years, and this observation was supported by the analysis of spontaneous reports. This suggests that a relation between COVID-19 vaccination and menstrual abnormalities is plausible and should be further investigated.

Vaccine effectiveness in symptom and viral load mitigation in COVID-19 breakthrough infections in South Korea

OBJECTIVES

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine effectiveness in coronavirus disease (COVID-19) patients with breakthrough infections has not been established in South Korea. To address this, we assessed the impact of vaccination on symptom occurrence and viral load.

METHODS

We performed a retrospective cohort study of 9,030 COVID-19 patients enrolled between February and November 2021. The impact of vaccination on the incidence of symptoms and viral load as indicated by cycle threshold (Ct) values of RdRp and E genes was evaluated using relative risks (RRs) and 95% confidence intervals (95% CIs).

RESULTS

Compared with unvaccinated patients, fully vaccinated patients were associated with a reduced symptom onset of cough, sputum, and myalgia in COVID-19 patients (RR (95% CI) = 0.86 (0.75-0.99) for cough; RR (95% CI) = 0.74 (0.56-0.98) for sputum; RR (95% CI) = 0.65 (0.53-0.79) for myalgia, respectively). Additionally, lower risk of high viral load, Ct value of RdRp gene <15 or Ct value of E gene <15, was observed especially in fully vaccinated patients younger than 40 years ((RR (95% CI) = 0.69 (0.49-0.96) for RdRp gene; (RR (95% CI) = 0.71 (0.53-0.95) for E gene).

CONCLUSION

SARS-CoV-2 vaccination was associated with a reduced risk of COVID-19 symptoms as well as decreased viral load, especially in patients younger than 40 years.

Herpesviruses reactivation following COVID-19 vaccination: a systematic review and meta-analysis

BACKGROUND

The reactivation of herpesviruses (HHV) in COVID-19 patients is evident in the literature. Several reports have been published regarding the reactivation of these viruses (HSV, VZV, EBV, and CMV) among those who got COVID-19 vaccines. In this study, we aimed to review the current evidence to assess whether HHVs reactivation has any association with the prior administration of COVID-19 vaccines.

METHODS

A systematic search was conducted on 25 September 2022 in PubMed/MEDLINE, Web of Science, and EMBASE. We included all observational studies, case reports, and case series which reported the reactivation of human herpesviruses following administration of COVID-19 vaccines.

RESULTS

Our systematic search showed 80 articles that meet the eligibility criteria. Among the evaluated COVID-19 vaccines, most of the vaccines were mRNA based. Evidence from observational studies showed the possible relation between COVID-19 vaccine administration and VZV and HSV reactivation. The results of our proportion meta-analysis showed that the rate of VZV reactivation among those who received the COVID-19 vaccine was 14 persons per 1000 vaccinations (95% CI 2.97-32.80). Moreover, our meta-analysis for HSV reactivation showed the rate of 16 persons per 1000 vaccinations (95% CI 1.06-46.4). Furthermore, the evidence from case reports/series showed 149 cases of HHV reactivation. There were several vaccines that caused reactivation including BNT162b2 mRNA or Pfizer-BioNTech (n = 76), Oxford-AstraZeneca (n = 22), mRNA-1273 or Moderna (n = 17), Sinovac (n = 4), BBIBP-CorV or Sinopharm (n = 3), Covaxin (n = 3), Covishield (n = 3), and Johnson and Johnson (n = 1). Reactivated HHVs included varicella-zoster virus (VZV) (n = 114), cytomegalovirus (CMV) (n = 15), herpes simplex virus (HSV) (n = 14), Epstein-Barr virus (EBV) (n = 6), and HHV-6 (n = 2). Most cases reported their disease after the first dose of the vaccine. Many patients reported having comorbidities, of which hypertension, diabetes mellitus, dyslipidemia, chicken pox, and atrial fibrillation were common.

CONCLUSION

In conclusion, our study showed the possible association between COVID-19 vaccination and herpesvirus reactivation. The evidence for VZV and HSV was supported by observational studies. However, regarding other herpesviruses (EBV and CMV), further research especially from observational studies and clinical trials is required to elucidate the interaction between COVID-19 vaccination and their reactivation.

Predictors of Pediatric COVID-19 vaccination: a case-control study in Tabriz, Iran

INTRODUCTION

COVID-19 vaccination of children can help reduce the severity of the infection and the death rate caused by it and also helps achieve herd immunity. The level of acceptance and high vaccination coverage is the main elements in the success of immunization programs. Children's vaccination is dependent on their parent's decision. This study aims to identify predictors of the children's COVID-19 vaccination accomplishment by their parents.

METHOD

In this case-control study, 577 vaccinated children as cases and 366 un-vaccinated children as controls were randomly selected from the general population of Tabriz, Iran 2022, and their data were collected by telephone calls and interviews with the children's parents. Cases and controls were compared in terms of clinical and demographic factors of the child as well as the socioeconomic status (SES) of their parents by using a multivariable mixed-effect logistic regression model.

RESULTS

According to the results of the multivariable logistic regression, the age of the child (OR = 1.26 95% CI (1.14, 1.40), p-value < 0.001), previous COVID-19 infection of the child (OR = 1.92, 95% CI (1.21, 3.04), p-value < 0.001), having no underlying disease in the child (OR = 1.76, 95% CI (1.02, 3.02), p-value = 0.04), the dwelling place of the household (the high-level dwelling in compared to a low level (OR = 3.34, 95% CI (1.6, 6.64), p-value = 0.001), the middle level of dwelling compared with low level (OR = 4.87, 95% CI (2.46, 9.51), p-value < 0.001)), and Father's job (Employee and technician Fathers compared to worker fathers (OR = 2.99, 95% CI (1.55, 5.77), p-value = 0.001)) were significant independent predictors of children COVID-19 vaccination.

CONCLUSION

Several demographic and socioeconomic factors were associated with children's vaccination. Older children, children without any underlying disease, children with a history of COVID-19 infection, and children of parents with higher levels of SES were more likely to receive the COVID-19 vaccine. This finding can be considered in children's vaccination policymaking.

Effectiveness and Safety of COVID-19 Vaccinations: An Umbrella Meta-Analysis

Objectives: This umbrella meta-analysis aims to provide comprehensive and synthesized evidence regarding the effectiveness and safety of COVID-19 vaccinations based on current studies. Methods: Studies from the Cochrane Library, PubMed, and EMBASE, published before 10 December 2021, were included in the analysis. The pooled results of effectiveness and safety were estimated and shown in forest plots. Results: We included nineteen studies (fifteen studies regarding safety and nine regarding effectiveness) in the analysis. The mRNA vaccines, adenovirus vector vaccines, subunit vaccines, and inactivated vaccines were found to be effective; however, mRNA vaccines, adenovirus vector vaccines and subunit vaccines were associated with local adverse events and systemic events when compared with inactivated vaccines. Conclusion: Our study suggested that till date, COVID-19 vaccination is still a preferred pharmaceutical way to control the widespread pandemic. However, all reported adverse events should be revisited to provide further evidence for mass vaccinations.

SARS-CoV-2 vaccine-triggered autoimmunity: Molecular mimicry and/or bystander activation of the immune system

Induced autoimmunity or autoinflammatory-like conditions as a rare vaccine-related adverse event have been reported following COVID-19 vaccination. Such inadvertent adverse reactions have raised somewhat concerns about the long-term safety of the developed vaccines. Such multifactorial phenomena may be related to the cross-reactivity between the viral-specific antigens with the host self-proteins through molecular mimicry mechanism and/or nonspecific bystander activation of the non-target antigen-independent immunity by the entities of the vaccine products. However, due to the low incidence of the reported/identified individuals and insufficient evidence, autoimmunity following the COVID-19 vaccination has not been approved. Thereby, it seems that further designated studies might warrant post-monitoring of the inevitable adverse immunologic reactions in the vaccinated individuals, especially among hypersensitive cases, to address possible immunological mechanisms induced by the viral vaccines, incorporated adjuvants, and even vaccine delivery systems.

The role of blood groups, vaccine type and gender in predicting the severity of side effects among university students receiving COVID-19 vaccines

On March 11^th, 2020, the World Health Organization (WHO) declared the coronavirus disease 2019 (COVID-19) a pandemic. To control the pandemic, billions of vaccine doses have been administered worldwide. Predictors of COVID-19 vaccine-related side effects are inconsistently described in the literature. This study aimed to identify the predictors of side effects' severity after COVID-19 vaccination among young adult students at Taif University (TU) in Saudi Arabia. An online, anonymous questionnaire was used. Descriptive statistics were calculated for numerical and categorical variables. Possible correlations with other characteristics were identified using the chi-square test. The study included 760 young adult participants from TU. Pain at the injection site (54.7%), headache (45.0%), lethargy and fatigue (43.3%), and fever (37.5%) were the most frequently reported COVID-19 vaccine-related side effects after the first dose. The most frequent side effects were reported among the 20-25-year-old age group for all doses of all vaccines. Females experienced remarkably more side effects after the second (p < 0.001) and third doses (p = 0.002). Moreover, ABO blood groups significantly correlated with vaccine-related side effects after the second dose (p = 0.020). The participants' general health status correlated with the side effects after the first and second doses (p < 0.001 and 0.022, respectively). The predictors of COVID-19 vaccine-related side effects in young, vaccinated people were blood group B, female gender, vaccine type, and poor health status.

Prevalence and risk factors of adverse effects after the first COVID-19 booster dose: evidence from Greece

Background

In general, COVID-19 vaccines are safe and effective, but minor adverse effects are common. However, adverse effects have not been measured in several countries including Greece.

Objective

To estimate the prevalence of adverse effects after the first COVID-19 booster dose, and to identify possible risk factors.

Material and methods

We conducted a cross-sectional study with a convenience sample in Greece during November 2022. We measured several adverse effects after the booster dose, such as fatigue, headaches, fever, chills, nausea, etc. We considered gender, age, chronic disease, self-assessment of health status, COVID-19 diagnóstico, and self-assessment of COVID-19 course as possible predictors of adverse effects.

Results

In our sample, 96% developed at least one adverse effect. Half of the participants (50.2%) developed one to five adverse effects, 35.9% developed six to ten adverse effects, and 9.5% developed 11 to 16 adverse effects. Mean number of adverse effects was 5.5. The most frequent adverse effects were pain at the injection site (84.3%), fatigue (70.8%), muscle pain (61%), swelling at the injection site (55.2%), headache (49.8%), fever (42.9%), and chills (41%). Females developed more adverse effects than males (p < 0.001). The prevalence of adverse effects of COVID-19 vaccines was statistically significant and positively associated with the severity of COVID-19 among COVID-recovered individuals (p < 0.05). Moreover, younger age was associated with increased adverse effects (p < 0.001).

Conclusions

Almost all participants in our study developed minor adverse effects after the booster dose. Female gender, COVID-19 patients with worse clinical course, and younger individuals experienced more often adverse effects.

The Role of Perceived Risk in the Relationship Between Disgust Sensitivity and COVID-19 Vaccine Hesitancy

Background

Despite widespread availability of COVID vaccines and evidence of their efficacy, vaccine hesitancy remains prevalent. Several studies have examined the relationship between disgust sensitivity and vaccine hesitancy. Although results from studies using data collected prior to the COVID pandemic indicate that higher disgust sensitivity is related to greater vaccine hesitancy, results from studies using data collected during the COVID pandemic are equivocal. The present study examined whether perceived risk of contracting COVID moderated the relationship between disgust sensitivity and vaccine hesitancy.

Methods

Participants (n = 152) completed self-report measures of disgust sensitivity, perceived risk of contracting COVID, and COVID vaccine hesitancy (defined as both vaccine confidence and vaccine complacency).

Results

Perceived risk of contracting COVID significantly moderated the relationship between disgust sensitivity and vaccine complacency, with the association strengthened at low levels of perceived risk. Perceived risk of contracting COVID also marginally moderated the relationship between disgust sensitivity and vaccine confidence, with the association strengthened at low and average levels of perceived risk.

Conclusions

Results suggest that individuals with elevated disgust sensitivity who also report low levels of perceived risk of contracting COVID are more likely to express vaccine hesitancy. Implications of these findings are discussed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10608-023-10391-8.

The efficacy and effectiveness of COVID-19 vaccines around the world: a mini-review and meta-analysis

OBJECTIVES

This meta-analysis evaluated the Efficacy and Effectiveness of several COVID-19 vaccines, including AstraZeneca, Pfizer, Moderna, Bharat, and Johnson & Johnson, to better estimate their immunogenicity, benefits, or side effects.

METHODS

Studies reporting the Efficacy and Effectiveness of COVID-19 vaccines from November 2020 to April 2022 were included. The pooled Effectiveness/Efficacy with a 95% confidence interval (95% CI) with Metaprop order was calculated. The results were presented in forest plots. Predefined subgroup analyses and sensitivity analyses were also performed.

RESULTS

A total of twenty articles were included in this meta-analysis. After the first dose of the vaccine, the total effectiveness of all COVID-19 vaccines in our study was 71% (95% CI 0.65, 0.78). The total effectiveness of vaccines after the second dose was 91% (95% CI 0.88, 0.94)). The total efficacy of vaccines after the first and second doses was 81% (95% CI 0.70, 0.91) and 71% (95% CI 0.62, 0.79), respectively. The effectiveness of the Moderna vaccine after the first and second dose was the highest among other studied vaccines ((74% (95% CI, 0.65, 0.83) and 93% (95% CI, 0.89, 0.97), respectively). The highest first dose overall effectiveness of the studied vaccines was against the Gamma variant (74% (95% CI, 0.73, 0.75)), and the highest effectiveness after the second dose was observed against the Beta variant (96% (95% CI, 0.96, 0.96)). The Efficacy for AstraZeneca and Pfizer vaccines after the first dose was 78% (95% CI, 0.62, 0.95) and 84% (95% CI, 0.77, 0.92), respectively. The second dose Efficacy for AstraZeneca, Pfizer, and Bharat was 67% (95% CI, 0.54, 0.80), 93% (95% CI, 0.85, 1.00), and 71% (95% CI, 0.61, 0.82), respectively. The overall efficacy of first and second dose vaccination against the Alfa variant was 84% (95% CI, 0.84, 0.84) and 77% (95% CI, 0.57, 0.97), respectively, the highest among other variants.

CONCLUSION

mRNA-based vaccines against COVID-19 showed the highest total efficacy and effectiveness than other vaccines. In general, administering the second dose produced a more reliable response and higher effectiveness than a single dose.

Safety and Efficacy of COVID-19 Vaccine in Africa: Systematic Review

Background

Coronavirus disease 2019 (COVID-19) pandemic scared the whole world at the end of 2019, which is a communicable respiratory disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). In South Africa and other African countries, the COVID-19 vaccines were subsequently approved for emergency use by the respective national regulatory authorities. There is a paucity of aggregated data that revealed the safety and efficacy of COVID-19 vaccines in Africa.

Objective

The aim of this systematic review was to synthesize the literature on the safety and efficacy of the COVID-19 vaccine which was given in Africa.

Methods

A systematic search was conducted on Science Direct, PubMed, EMBASE, Google Scholar, CINAHL, Cochrane Library, and direct Google searches. Only studies written in English and published articles from 2019 to October 30, 2022, which comprise nine randomized clinical trials (RCT), and four different studies including a single-arm implementation trials, prospective study, retrospective cohort study, and test-negative designs were included.

Results

A total of 13 studies were included which contain 810,466 participants from Africa. Of these, 62.18% of the participants were female. The efficacy of COVID-19 vaccine in Africa ranges from 41.7% to 100%. Moreover, vaccine efficacy against COVID-19 variants ranges from -5.7% to 100%. In general, systemic and local adverse events following vaccination in most trials were reported with a similar pattern between the placebo and vaccine groups. Out of the total reported adverse events, most of them were mild to moderate, whereas a few were serious.

Conclusion

Almost all current COVID-19 vaccines appear to be safe for African study participants. Regarding efficacy, the protein subunit vaccine and mRNA vaccine exhibited high efficacy (100%) in this group of participants. However, Ad26. COV2.S and ChAdOx1 nCoV-19 COVID-19 vaccines are not effective against the delta variant and B.1.351 variant, respectively.

Assessing vaccine safety during a pandemic: Recent experience and lessons learned for the future

During the roll out of vaccines during a pandemic, questions regarding vaccine safety often arise. This was surely true during the SARS-CoV-2 pandemic. Different tools and capabilities exist during the pre-authorization phase and post introduction each with its strengths and limitations. Here we review the various tools and their strengths and limitations and discuss what functioned well in high income settings and the limitations that unequal vaccine safety pharmacovigilance capacity imposed upon middle and low income countries.