An Overview Of Vaccine Development, Approval, And Regulation, With Implications For COVID-19

Establishing a Framework for Evaluating the Effectiveness of Vaccines Targeting National Vaccination Programs

BACKGROUND

The increasing number of vaccines and the complexity of immunization programs, along with continuous changes in the epidemiology of infectious diseases, necessitate a systematic approach to vaccine effectiveness (VE) evaluation. This study presents a preliminary survey to establish a VE evaluation framework in Korea, focusing on the National Immunization Program.

METHODS

Experts' opinions were collected through a two-round online survey targeting key stakeholders. The first round consisted of two multiple-choice questions and two open-ended questions. The second round was a quantitative survey with 17 questionnaires based on five domains derived by analyzing the results of the first-round survey.

RESULTS

The results emphasize the necessity and urgency of a government-led VE evaluation system and the establishment of a multidisciplinary evaluation organization. Key considerations include personnel, budget, data integration, legal standards, and surveillance system enhancements.

CONCLUSION

These findings provide valuable insights for policymakers, emphasizing the need for collaboration, financial support, and robust data management in developing evidence-based vaccination policies.

Impact of vitamin D supplementation as COVID-19 vaccine adjuvant on sperm parameters and sex hormones in men with idiopathic infertility: Two separate pre-post studies

OBJECTIVE

Vitamin D deficiency is a major problem for human health worldwide. The mechanisms of vitamin D in the male reproductive system are unknown. After coronavirus disease 2019 (COVID-19) vaccines were developed, doubts were raised about their possible effects on male fertility. Based on vitamin D's function in the immune system, its potential role as an adjuvant for COVID-19 vaccines is intriguing. The aims of this study were to assess the effects of vitamin D first on sperm parameters and sex hormones, and then as an immune adjuvant on sperm parameters and sex hormones after study participants had received their second doses of COVID-19 vaccines.

METHODS

Phase 1 (before the COVID-19 pandemic) included 72 men with idiopathic infertility, and phase 2 had 64 participants who received two doses of COVID-19 vaccines. Both groups were instructed to take 50,000 IU of vitamin D twice monthly for 3 months. Sperm parameters and sex hormones were assessed pre- and post-supplementation.

RESULTS

Regular vitamin D intake for 3 months significantly increased the participants' vitamin D levels (p=0.0001). Both phases showed a positive correlation between vitamin D intake and sperm parameters. Vaccination had no negative effects on sperm parameters and sex hormones. Vitamin D was associated with follicle-stimulating hormone (p=0.02) and testosterone (p=0.0001) in phase 2 after treatment.

CONCLUSION

Our results support vitamin D supplementation as an immune adjunct to COVID-19 vaccination for improving sperm parameters and hormone levels. COVID-19 vaccination is not harmful for male fertility potential, and vitamin D is an effective factor for male fertility.

Emergency Regulatory Procedures, Pharmaceutical Regulatory Politics, and the Political Economy of Vaccine Regulation in the COVID-19 Pandemic

CONTEXT

Regulatory approaches to COVID-19 vaccine authorizations varied substantially across countries. Facing a common public health threat, what accounts for regulatory variation? This study focuses on emergency pharmaceutical and vaccine regulatory procedures and whether and how regulators' emergency pharmaceutical regulatory procedures going into the pandemic shaped regulatory processes and decisions during the pandemic.

METHODS

The authors conducted an analysis of seven high-impact national and international pharmaceutical regulators with case studies from Brazil, China, India, Russia, the United Kingdom, the United States, and the European Medicines Agency. The authors analyzed evidence from primary source executive and legislative branch regulations and statutes as well as national and international scientific and general press reporting; they also drew on the secondary analysis of scholars, practitioners, and international organizations.

FINDINGS

Inherited emergency pharmaceutical and vaccine regulatory procedures substantially shaped COVID-19 vaccine regulation during the pandemic. Variation in the presence and content of emergency regulatory procedures affected the quality of pandemic regulatory processes, outcomes, and procedural updates and differentially empowered policy-making experts and elected politicians.

CONCLUSIONS

Emergency regulatory procedures affect key features of regulatory political economy and public health practices during crises. To improve future public health crisis responses, the authors provide policy recommendations for (1) establishing clear emergency pharmaceutical regulatory procedures, and (2) international collaboration.

Heterologous booster with a novel formulation containing glycosylated trimeric S protein is effective against Omicron

In this study, we evaluated the efficacy of a heterologous three-dose vaccination schedule against the Omicron BA.1 SARS-CoV-2 variant infection using a mouse intranasal challenge model. The vaccination schedules tested in this study consisted of a primary series of 2 doses covered by two commercial vaccines: an mRNA-based vaccine (mRNA1273) or a non-replicative vector-based vaccine (AZD1222/ChAdOx1, hereafter referred to as AZD1222). These were followed by a heterologous booster dose using one of the two vaccine candidates previously designed by us: one containing the glycosylated and trimeric spike protein (S) from the ancestral virus (SW-Vac 2µg), and the other from the Delta variant of SARS-CoV-2 (SD-Vac 2µg), both formulated with Alhydrogel as an adjuvant. For comparison purposes, homologous three-dose schedules of the commercial vaccines were used. The mRNA-based vaccine, whether used in heterologous or homologous schedules, demonstrated the best performance, significantly increasing both humoral and cellular immune responses. In contrast, for the schedules that included the AZD1222 vaccine as the primary series, the heterologous schemes showed superior immunological outcomes compared to the homologous 3-dose AZD1222 regimen. For these schemes no differences were observed in the immune response obtained when SW-Vac 2µg or SD-Vac 2µg were used as a booster dose. Neutralizing antibody levels against Omicron BA.1 were low, especially for the schedules using AZD1222. However, a robust Th1 profile, known to be crucial for protection, was observed, particularly for the heterologous schemes that included AZD1222. All the tested schedules were capable of inducing populations of CD4 T effector, memory, and follicular helper T lymphocytes. It is important to highlight that all the evaluated schedules demonstrated a satisfactory safety profile and induced multiple immunological markers of protection. Although the levels of these markers were different among the tested schedules, they appear to complement each other in conferring protection against intranasal challenge with Omicron BA.1 in K18-hACE2 mice. In summary, the results highlight the potential of using the S protein (either ancestral Wuhan or Delta variant)-based vaccine formulation as heterologous boosters in the management of COVID-19, particularly for certain commercial vaccines currently in use.

Large-deviations of disease spreading dynamics with vaccination

We numerically simulated the spread of disease for a Susceptible-Infected-Recovered (SIR) model on contact networks drawn from a small-world ensemble. We investigated the impact of two types of vaccination strategies, namely random vaccination and high-degree heuristics, on the probability density function (pdf) of the cumulative number C of infected people over a large range of its support. To obtain the pdf even in the range of probabilities as small as 10-80, we applied a large-deviation approach, in particular the 1/t Wang-Landau algorithm. To study the size-dependence of the pdfs within the framework of large-deviation theory, we analyzed the empirical rate function. To find out how typical as well as extreme mild or extreme severe infection courses arise, we investigated the structures of the time series conditioned to the observed values of C.

The United States Food and Drug Administration (FDA) regulatory response to combat neglected tropical diseases (NTDs): A review

The availability and accessibility of safe and effective drugs, vaccines, and diagnostics are essential to reducing the immense global burden of neglected tropical diseases (NTDs). National regulatory authorities, such as the United States Food and Drug Administration (FDA), play an essential role in this effort to ensure access to safe and effective medical products by working within a set of legal frameworks and regulatory functions. However, medical product development for NTDs remains neglected, as combating NTDs is not a viable commercial market for pharmaceutical companies. To spur research and development (R&D) of NTD products, the US government has authorized various programs and policies to engage pharmaceutical companies, many of which provide FDA with the legal authority to implement NTD programs and pathways. Thus, this review provides a clear overview of the various regulatory pathways and programs employed by the FDA to increase the availability of NTD drugs, vaccines, and diagnostics. The review assesses the available information on various regulatory considerations and their impact on NTD product development as a first step in estimating the importance of such programs. Next, findings related to currently approved NTD products through these programs are discussed. Lastly, gaps in NTD R&D are identified and suggestions on how to address these are presented. The available data shows that while such incentive programs are factored into companies' decisions to pursue NTD R&D, approved products for NTDs remains vastly insufficient. Most approved products that utilize these NTD regulatory pathways and programs are overwhelmingly for tuberculosis and malaria-both of which are not considered NTDs by the World Health Organization (WHO). Dedicated efforts are needed to facilitate and accelerate NTD product including employing multiple incentive programs, regular assessment of such programs, and leveraging on public-private partnerships.

Virtual screening and structure-based 3D pharmacophore approach to identify small-molecule inhibitors of SARS-CoV-2 Mpro

The outbreak caused by a coronavirus 2 has required quick and potential treatment strategies. The main protease enzyme M^pro plays an important role in the viral replication which renders it an important target for discovering SARS-CoV-2 inhibitors. In this study, 3D pharmacophore structure-based virtual screening and molecular docking were conducted using MOE and Bristol University Docking Engine (BUDE). Around 400,000 molecules of ZINC15 database were docked against the crystal structure of main protease, followed by 3D pharmacophore filtration. Six top-ranked hits (ZINC58717986, ZINC60399606, ZINC58662884, ZINC45988635, ZINC54706757 and ZINC17320595) were identified based on their strong spatial affinity and forming H-bonds with key residues H41, E166, Q189 and T190 of the binding pocket of M^pro SARS-CoV-2. The 6 hits subjected to molecular dynamics simulations for 100 ns followed by binding free energy calculations using MM-PBSA technique. Interestingly, three hits showed free binding energy (ΔG_binding) lower than tert-butyl N-[1-[(2S)-1-[[(2S)-4-(benzylamino)-3,4-dioxo-1-[(3S)-2-oxopyrrolidin-3-yl]butan-2-yl]amino]-3-cyclopropyl-1-oxopropan-2-yl]-2-oxopyridin-3-yl]carbamate (α-ketoamide 13 b) (ΔG_binding) -76.67 ± 0.5 kJ/mol which suggested their potential against SARS-CoV-2. The best binding free energy candidates, ZINC58717986 (ΔG_binding) -98.41 ± 0.7 kJ/mol. The second-best hit candidate, ZINC54706757 (ΔG_binding) -83.4 ± 0.6 kJ/mol and the third one ZINC17320595 (ΔG_binding) -78.85 ± 0.5 kJ/mol. Per residue decomposition free energy indicates H41, S46, H164, E166, D187, Q189 and Q192 are hot spot residues while residues M49, M165, L167 and P168 contribute to the hydrophobic interactions. The pharmacokinetic study suggests that the selected 6 hits possess drug-like properties. The 3D pharmacophore virtual screening, molecular dynamics and MM-PBSA approaches facilitated identification 3 promising hits with low free binding energy as SARS-CoV-2 inhibitors.Communicated by Ramaswamy H. Sarma.

Trends in the Quality of Evidence Supporting FDA Drug Approvals: Results from a Literature Review

CONTEXT

New drug approvals in the United States must be supported by substantial evidence from "adequate and well-controlled" trials. The Food and Drug Administration (FDA) has flexibility in how it applies this standard.

METHODS

The authors conducted a systematic literature review of studies evaluating the design and outcomes of the key trials supporting new drug approvals in the United States. They extracted data on the trial characteristics, endpoint types, and expedited regulatory pathways.

FINDINGS

Among 48 publications eligible for inclusion, 30 covered trial characteristics, 23 covered surrogate measures, and 30 covered regulatory pathways. Trends point toward less frequent randomization, double-blinding, and active controls, with variation by drug type and indication. Surrogate measures are becoming more common but are not consistently well correlated with clinical outcomes. Drugs approved through expedited regulatory pathways often have less rigorous trial design characteristics.

CONCLUSIONS

The characteristics of trials used to approve new drugs have evolved over the past two decades along with greater use of expedited regulatory pathways and changes in the nature of drugs being evaluated. While flexibility in regulatory standards is important, policy changes can emphasize high-quality data collection before or after FDA approval.

Recent advances in the vaccine development for the prophylaxis of SARS Covid-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-caused Coronavirus Disease 2019 (COVID-19) is currently a global pandemic that has wreaked havoc on public health, lives, and the global economy. The present COVID-19 outbreak has put pressure on the scientific community to develop medications and vaccinations to combat COVID-19. However, according to highly optimistic forecasts, we could not have a COVID-19 vaccine until September 2020. This is due to the fact that a successful COVID-19 vaccine will necessitate a careful validation of effectiveness and adverse reactivity given that the target vaccine population includes high-risk people over 60, particularly those with severe co-morbid conditions, frontline healthcare professionals, and those involved in essential industrial sectors. For passive immunization, which is being considered for Covid-19, there are several platforms for vaccine development, each with its own advantages and disadvantages. The COVID-19 pandemic, which is arguably the deadliest in the last 100 years after the Spanish flu, necessitates a swift assessment of the various approaches for their ability to incite protective immunity and safety to prevent unintended immune potentiation, which is crucial to the pathogenesis of this virus. Considering the pandemic's high fatality rate and rapid spread, an efficient vaccination is critical for its management. As a result, academia, industry, and government are collaborating in unprecedented ways to create and test a wide range of vaccinations. In this review, we summarize the Covid-19 vaccine development initiatives, recent trends, difficulties, comparison between traditional vaccines development and Covid-19 vaccines development also listed the approved/authorized, phase-3 and pre-clinical trials Covid-19 vaccines in different countries.

COVID-19 and vaccination: myths vs science

INTRODUCTION

Several vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed since the inception of the coronavirus disease 2019 (COVID-19) in December 2019, at unprecedented speed. However, these rapidly developed vaccines raised many questions related to the efficacy and safety of vaccines in different communities across the globe. Various hypotheses regarding COVID-19 and its vaccines were generated, and many of them have also been answered with scientific evidence. Still, there are many myths/misinformation related to COVID-19 and its vaccines, which create hesitancy for COVID-19 vaccination, and must be addressed critically to achieve success in the battle against the pandemic.

AREA COVERED

The development of anti-SARS-CoV-2 vaccines against COVID-19, their safety and efficacy, and myths/misinformation relating to COVID-19 and vaccines are presented.

EXPERT OPINION

In this pandemic we have seen a global collaborative effort of researchers, governments, and industry, supported by billions of dollars in funding, have allowed the development of vaccines far more quickly than in the past. Vaccines go through rigorous testing, analysis, and evaluations in clinical settings prior to their approval, even if they are approved for emergency use. Despite the myths, vaccination represents an important strategy to get back to normality.

Status of Planned and Ongoing Paediatric Trials Investigating COVID-19 Vaccines: A Cross-Sectional Study of Paediatric Clinical Trials Planned in Agreed PIPs and/or Registered in Clinical Trial Databases

Background

The immune system matures throughout childhood; therefore, evidence about the safety and efficacy of vaccines for the prevention of COVID-19 in the paediatric population is important. Efficacy and safety have not been established for COVID-19 vaccines in a large part of the paediatric population at the time of the initial approval for use in adults. This study aims to provide an overview of planned and ongoing paediatric clinical trials investigating the safety and/or efficacy of COVID-19.

Methods

We identified all paediatric clinical trials investigating the safety and/or efficacy of COVID-19 vaccines in clinicaltrials.gov and clinicaltrialregister.eu, as well as all clinical trials planned in agreed PIPs (Paediatric Investigational Plans) as of 11 June 2021. Information about the study design, the paediatric age groups that they included, and the primary and secondary safety and efficacy outcomes were collected, together with expected timelines for the studies.

Results

21 clinical trials were identified through the clinical trial registries and 19 clinical trials were specified in 6 agreed PIPs, 5 of these trials were also in the trial registers. All PIPs stipulated development of the COVID-19 vaccines for the full paediatric population, with a deferral. The earliest expected completion date of a PIPs is March 2024. The majority (14/21) of registered trials are randomised double-blinded studies. All investigated safety, 20 have a surrogate efficacy outcome (immunogenicity), of these 7 also measure clinical efficacy (COVID-19 infections). 18 studies were initiated, of these, all but one is still ongoing and one in adolescents has been finalised.

Conclusion

Even though several trials have been planned in agreed PIPs, the registered paediatric clinical trials identified are most often not part of a PIP.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43441-021-00356-y.

COVID-19 Pandemic and Trends in Clinical Trials: A Multi-Region and Global Perspective

To evaluate the effect of the COVID-19 pandemic on clinical development, the number of newly started clinical trials in each geographical region between January 2018 and December 2020 were calculated based on data from the ClinicalTrials.gov database. Data regarding new drug applications were obtained from European Medicines Agency monthly reports, pharmaceutical company press releases, and the archives of the Drugs.com database. The mean percentage change in newly started clinical trials for diseases other than COVID-19 between each month in 2019 and the corresponding month in 2020 was −7.5%, with the maximum of −57.3% observed between April 2019 and April 2020. Similarly, the mean percentage change of reported results for each month in 2019 and 2020 was −5.1%, with the maximum of −27.4% observed in July 2020. The activity of clinical trials was decreased as the number of COVID-19 patients was increased, and a statistically negative correlation was observed between the prevalence of COVID-19 and the percentage decrease in the number of clinical trials stared or reported results. As for new drug submissions, decreases were observed in the latter half of 2020 compared with the same period during the previous year, for each indicator. A considerable decline in non-COVID-19 activity for all indicators regarding clinical developments was suggested during the first wave of the COVID-19 pandemic. It is important to recognize the situation and continue to make efforts to conduct clinical trials for both COVID-19 and no-COVID-19 for new medical developments in the future.

Implications of attitudes and beliefs about COVID-19 vaccines for vaccination campaigns in the United States: A latent class analysis

Unprecedented global efforts in vaccine development have resulted in effective vaccines for COVID-19. The pandemic response in the US has been highly politicized, resulting in significant opposition to public health efforts, including vaccines. We aimed to understand patterns of attitudes and beliefs about the COVID-19 vaccine to inform vaccination campaigns. 583 English speaking United States adults were surveyed November 18-29, 2020. Participants answered 11 questions about their attitudes and beliefs about a COVID-19 vaccine, including perceived vaccine effectiveness, likelihood of getting vaccinated, and concerns that vaccine development was rushed/influenced by politics. We conducted a latent class analysis to identify profiles of attitudes/beliefs about a COVID-19 vaccine. We identified four classes of COVID-19 vaccine beliefs. The pro-vaccine class (28.8%) was willing to get vaccinated and had broadly positive beliefs about the vaccine. The development concerns class (27.8%) was willing to get vaccinated but was concerned about the development process. The third class (22.6%) was largely unsure if they would get vaccinated and if their peer groups would be vaccinated. The forth class (anti-vaccine, 20.8%) was dominated by an unwillingness to get vaccinated, vaccine distrust, vaccine development concerns, and peers groups with negative vaccine intentions. Given the large proportion of individuals who were concerned about the COVID-19 vaccine development process, messaging about rigor and approval processes may be critical to securing this group's commitment to vaccination. Having scientific and cultural leaders endorse vaccination may also be influential.

Non-Toxic Dimeric Peptides Derived from the Bothropstoxin-I Are Potent SARS-CoV-2 and Papain-like Protease Inhibitors

The COVID-19 outbreak has rapidly spread on a global scale, affecting the economy and public health systems throughout the world. In recent years, peptide-based therapeutics have been widely studied and developed to treat infectious diseases, including viral infections. Herein, the antiviral effects of the lysine linked dimer des-Cys¹¹, Lys¹²,Lys¹³-(pBthTX-I)₂K ((pBthTX-I)₂K)) and derivatives against SARS-CoV-2 are reported. The lead peptide (pBthTX-I)₂K and derivatives showed attractive inhibitory activities against SARS-CoV-2 (EC₅₀ = 28–65 µM) and mostly low cytotoxic effect (CC₅₀ > 100 µM). To shed light on the mechanism of action underlying the peptides’ antiviral activity, the Main Protease (M^pro) and Papain-Like protease (PL^pro) inhibitory activities of the peptides were assessed. The synthetic peptides showed PL^pro inhibition potencies (IC₅₀s = 1.0–3.5 µM) and binding affinities (K_d = 0.9–7 µM) at the low micromolar range but poor inhibitory activity against M^pro (IC₅₀ > 10 µM). The modeled binding mode of a representative peptide of the series indicated that the compound blocked the entry of the PL^pro substrate toward the protease catalytic cleft. Our findings indicated that non-toxic dimeric peptides derived from the Bothropstoxin-I have attractive cellular and enzymatic inhibitory activities, thereby suggesting that they are promising prototypes for the discovery and development of new drugs against SARS-CoV-2 infection.

The willingness of the Saudi Arabian population to participate in the COVID-19 vaccine trial: A case-control study

OBJECTIVES

This study examines the Saudi Arabian population's willingness to participate in clinical trials for the coronavirus disease 2019 (COVID-19) vaccine, comparing recovered cases' willingness with that of healthy volunteers.

METHODS

A case-control study was conducted on the Saudi Arabian population during September 2020. The data were collected from recovered COVID-19 participants as the case group, and healthy volunteers as the control group.

RESULTS

The data showed that 42.2% (n = 315) of recovered COVID-19 cases were more willing to participate in the COVID-19 vaccine trial than healthy volunteers (299; 38.1%) with a p < 0.001. The proportion of the participants who were willing to donate plasma was significantly higher among recovered participants, 84.2% (n = 112), than healthy volunteers, 76.3% (n = 87), with a p < 0.0001. The most significant factor responsible for a willingness to participate was the belief that vaccine discovery would help scientific developments (r = 0.525 and 0.465 for case and control, respectively). In comparison, significant reasons behind the unwillingness to participate were the risk of exposure to an unproven vaccine, r = 0.377 and 0.497 for case and control, respectively (p < 0.001), and a discomfort with being treated as an experimental subject (r = 0.275 and 0.374 for case and control, respectively).

CONCLUSIONS

The differences in readiness toward the COVID-19 vaccine trial in our study does not indicate any passive exposure of participants to an unproven clinical trial vaccine, nor does it shed light on well-informed risk-related decisions. However, certain factors can significantly influence decision-making while contributing toward clinical research. This study's results must not be used for the individuals' recruitment bias in a COVID-19 vaccine trial.

Forty days of regulatory emergency use authorisation of COVID-19 vaccines: Interfacing efficacy, hesitancy and SDG target 3.8

The year 2020 will be synonymous with the coronavirus disease 2019 (COVID-19) for many global citizens. Millions have died from and tens of millions more have been infected globally by the COVID-19 pandemic. This has led to an urgent search for COVID-19 vaccines and treatments by the scientific and political communities and civil society. Through elements of events study and document and critical discourse analysis, this paper investigates the COVID-19 vaccines' regulatory emergency use authorisation and/or conditional marketing authorisation (regulatory authorisation) regimes and the contestations thereof. The key finding is that there was a regulatory authorisation rush, with at least 62, mostly high-income countries, doing so in 40 days from 2 December 2020-10 January 2021. This has led to one senior USA official describing the United Kingdom pioneer regulatory authorisation of the Pfizer-BioNTech vaccine as 'too quick'. Regulatory authorisation regimes took place amid severe civil society contestations and appropriate political pressure. The paper recommends that as the COVID-19 vaccines' regulatory authorisation continue in 2021, national vaccines and treatments regulatory bodies must be informed by science, with governments, civil society, politicians and other key stakeholders taking responsibility to educate the masses and continue taking the necessary precautions.

Characteristics of Postmarketing Studies for Vaccines Approved by the US Food and Drug Administration, 2006-2020

This cross-sectional study uses data from the US Food and Drug Administration (FDA) to review the postmarketing requirements and commitments attached to new vaccines approved for use in the past 15 years in the United States.

Evaluation of Post-Vaccination Symptoms of Two Common COVID-19 Vaccines Used in Abha, Aseer Region, Kingdom of Saudi Arabia

BACKGROUND

The Pfizer-BioNTech (BNT162b2) and the Oxford-AstraZeneca (ChAdOx1 nCoV-19) COVID-19 vaccines have shown promising safety and acceptability. However, COVID-19 vaccine side effects play an essential role in public vaccine confidence. We aimed to study the side effects of these COVID-19 vaccines.

METHODS

A randomized, cross-sectional descriptive study was conducted between March and May of 2021. In total, 330 participants among the King Khalid University community in the Aseer region of the Kingdom of Saudi Arabia reported their side effects following the COVID-19 vaccine. A questionnaire was designed and validated to collect the participants' demographic data and COVID-19-related symptoms after COVID-19 vaccine injection.

RESULTS

Symptoms associated with COVID-19 were reported by 226 participants (68.5%). The most common side effects reported by the participants were fever (n = 136, 41.2%), fatigue (n = 119, 36.1%), headache (n = 86, 24.2%), malaise (n = 121, 36.7%), myalgia (n = 121, 36.7%), and muscle and joint pain (n = 76, 23%). Of the participants, 5.1% became infected with COVID-19 after vaccination. Symptoms were significantly more common in males than in females (p = 0.006).

CONCLUSION

The incidence of COVID-19 vaccination side effects in the Aseer region, Kingdom of Saudi Arabia, was consistent with the manufacturers' data. The most common post-vaccination symptoms reported by the participants were fever, myalgia, malaise, fatigue, muscle and joint pain, and headache. The results of this study showed significant variation in adverse events between Pfizer-BioNTech and Oxford-AstraZeneca COVID-19 vaccines. Healthcare providers and recipients of vaccines can be more confident about the safety of Pfizer-BioNTech and Oxford-AstraZeneca COVID-19 vaccines.