Evaluation of the safety profile of COVID-19 vaccines: a rapid review

Immunogenicity, Safety, and Immune Persistence of One Dose of SARS-CoV-2 Recombinant Adenovirus Type-5 Vectored Vaccine in Children and Adolescents Aged 6-17 Years: An Immunobridging Trial

BACKGROUND

Though children infected by SARS-CoV-2 generally experience milder symptoms compared to adults, severe cases can occur. Additionally, children can transmit the virus to others. Therefore, the availability of safe and effective COVID-19 vaccines for children and adolescents is crucial.

METHOD

A single-center, randomized, double-blind clinical trial was conducted in Funing County, Yancheng City, Jiangsu Province, China. Healthy children and adolescents were divided into two subgroups (6-12 years old or 13-17 years old) and randomly assigned to one of three groups to receive one dose of Ad5-nCoV (3 × 1010 vp/dose). Another group, aged 18-59, received one dose of Ad5-nCoV (5 × 1010 vp/dose) as the control group. At 28, 90, 180, and 360 days post-vaccination, we measured the geometric mean titer (GMT)/concentration (GMC) of neutralizing and binding antibodies against the prototype SARS-CoV-2 strain, as well as serum antibody levels against the BA.4/5 variant. We also evaluated the incidence of adverse events within 28 days post-vaccination.

RESULTS

A total of 2413 individuals were screened from 3 June 2021 to 25 July 2021, of whom 2021 eligible participants were enrolled, including 1009 aged 6~17 years in the children and adolescent group and 1012 aged 18-59 years in the adults group. The GMT of anti-wild SARS-CoV-2 neutralizing antibodies was 18.6 (95% CI, 16.6-20.9) in children and adolescents and 13.2 (95% CI, 11.6-15.0) in adults on day 28. The incidence of solicited adverse reactions between the adult group (49.4% [124/251]) and the children and adolescent group (46.3% [156/337]) was not statistically significant. The neutralizing antibody levels decreased by a factor of 3.29 from day 28 to day 360 post-vaccination.

CONCLUSIONS

A single dose of Ad5-nCoV at 3 × 1010 virus particles/dose is safe in children and adolescents, and it elicited significant immune response, which was not only non-inferior but also superior to that in adults aged 18-59 years.

Safety Assessment of Concurrent Vaccination with the HPV Vaccine and the COVID-19 Vaccine in Fujian Province, China: A Retrospective Study

During acute respiratory infections, women may concurrently receive human papillomavirus (HPV) and respiratory vaccines, as observed during the coronavirus disease 2019 (COVID-19) pandemic in China. However, few studies have assessed the safety of such concurrent administration, which could impact HPV vaccination schedules. This study analyzes the safety and optimal sequence of concurrent HPV and COVID-19 vaccinations. For this purpose, we surveyed women with both vaccines from January to October 2023 in Fujian Province, China. During this process, we collected vaccination history and adverse event (AE) data via telephone or interviews. Participants were grouped as Before, Concurrent, or After based on their vaccination sequence. A Chi-squared test, exact Fisher tests, and logistic regression were used to analyze the incidence of AEs and factors influencing vaccine safety. Overall, 1416 eligible participants were included. Although overall AE risk with the HPV vaccine was unaffected by vaccination sequence, individual AEs varied statistically between groups, including pain at the vaccination site (p < 0.001) and prolonged menstruation duration (p = 0.003). Based on the results, the optimal sequence would be to receive the HPV vaccine after the COVID-19 vaccine (After group). This insight may guide future emergency vaccination sequences for HPV and other respiratory infectious diseases.

Association between adverse events after COVID-19 vaccination and anti-SARS-CoV-2 antibody concentrations, the Netherlands, May 2021 to November 2022: a population-based prospective cohort study

BackgroundNon-severe adverse events (AE) including pain at injection site or fever are common after COVID-19 vaccination.AimTo describe determinants of AE after COVID-19 vaccination and investigate the association between AE and pre- and post-vaccination antibody concentrations.MethodsParticipants of an ongoing prospective cohort study (VASCO) completed a questionnaire on AE within 2 months after vaccination and provided 6 monthly serum samples during May 2021-November 2022. Logistic regression analyses were performed to investigate AE determinants after mRNA vaccination, including pre-vaccination Ig antibody concentrations against the SARS-CoV-2 spike protein receptor binding domain. Multivariable linear regression was performed in SARS-CoV-2-naive participants to assess the association between AE and log-transformed antibody concentrations 3-8 weeks after mRNA vaccination.ResultsWe received 47,947 completed AE questionnaires by 28,032 participants. In 42% and 34% of questionnaires, injection site and systemic AE were reported, respectively. In 2.2% of questionnaires, participants sought medical attention. AE were reported more frequently by women, younger participants (< 60 years), participants with medical risk conditions and Spikevax recipients (vs Comirnaty). Higher pre-vaccination antibody concentrations were associated with higher incidence of systemic AE after the second and third dose, but not with injection site AE or AE for which medical attention was sought. Any AE after the third dose was associated with higher post-vaccination antibody concentrations (geometric mean concentration ratio: 1.38; 95% CI: 1.23-1.54).ConclusionsOur study suggests that high pre-vaccination antibody levels are associated with AE, and experiencing AE may be a marker for higher antibody response to vaccination.

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.

Effectiveness and safety of immune response to SARS‑CoV‑2 vaccine in patients with chronic kidney disease and dialysis: A systematic review and meta‑analysis

The coronavirus disease 2019 (COVID-19) vaccination is the most effective way to prevent COVID-19. However, for chronic kidney disease patients on long-term dialysis, there is a lack of evidence regarding the efficacy and safety of the immune response to the vaccine. The present meta-analysis explores the efficacy and safety of COVID-19 vaccine in the immune response of patients with chronic kidney disease (CKD) undergoing dialysis. PubMed, Web of Science, Science Direct, and Cochrane Library databases were systematically searched from January 1, 2020, to December 31, 2022. Data analysis was performed using REVMAN 5.1s and Stata14 software. Baseline data and endpoint events were extracted, mainly including age, sex, dialysis vintage, body mass index (BMI), vaccine type and dose, history of COVID-19 infection, seropositivity rate, antibody titer, pain at injection site, headache and other safety events. The meta-analysis included 33 trials involving 81,348 patients. The immune efficacy of patients with CKD and dialysis was 80% (95 CI, 73-87%). The seropositivity rate of individuals without COVID-19 infection was 76.48% (3,824/5,000), while the seropositivity rate of individuals with COVID-19 infection was 80.82% (1,858/2,299). The standard mean difference of antibody titers in CKD and dialysis patients with or without COVID-19 infection was 27.73 (95% CI, -19.58-75.04). A total of nine studies reported the most common adverse events: Pain at the injection site, accounting for 18% (95 CI, 6-29%), followed by fatigue and headache, accounting for 8 (95 CI, 4-13%) and 6% (95 CI, 2-9%), respectively. COVID-19 vaccine benefitted patients with CKD undergoing dialysis with seropositivity rate ≥80%. Adverse events such as fatigue, headache, and pain at the injection site may occur after COVID-19 vaccination but the incidence is low.

COVID-19 vaccine reactogenicity among participants enrolled in the GENCOV study

BACKGROUND

GENCOV is a prospective, observational cohort study of COVID-19-positive adults. Here, we characterize and compare side effects between COVID-19 vaccines and determine whether reactogenicity is exacerbated by prior SARS-CoV-2 infection.

METHODS

Participants were recruited across Ontario, Canada. Participant-reported demographic and COVID-19 vaccination data were collected using a questionnaire. Multivariable logistic regression was performed to assess whether vaccine manufacturer, type, and previous SARS-CoV-2 infection are associated with reactogenicity.

RESULTS

Responses were obtained from n = 554 participants. Tiredness and localized side effects were the most common reactions across vaccine doses. For most participants, side effects occurred and subsided within 1-2 days. Recipients of Moderna mRNA and AstraZeneca vector vaccines reported reactions more frequently compared to recipients of a Pfizer-BioNTech mRNA vaccine. Previous SARS-CoV-2 infection was independently associated with developing side effects.

CONCLUSIONS

We provide evidence of relatively mild and short-lived reactions reported by participants who have received approved COVID-19 vaccines.

Efficacy, immunogenicity, and safety of COVID-19 vaccines in individuals with liver cirrhosis: a rapid review and meta-analysis

The emergence of coronavirus disease 2019 (COVID-19) vaccines has been a remarkable advancement. However, the efficacy, immunogenicity, and safety of these vaccines in individuals with liver cirrhosis require careful evaluation due to their compromised immune status and potential interactions with underlying liver disease. The present study aimed to evaluate the safety and efficacy of COVID-19 vaccines in liver cirrhosis patients. In the present study, we searched international databases, including Google Scholar, PubMed, Scopus, Embase, and Web of Science. The search strategy was carried out by using keywords and MeSH (Medical Subject Headings) terms. STATA ver. 15.0 (Stata Corp., USA) was used to analyze the data statistically. The analysis was performed using the random-effects model. We also used the chi-square test and I2 index to calculate heterogeneity among studies. For evaluating publication bias, Begg's funnel plots and Egger's tests were used. A total of 4,831 liver cirrhosis patients with COVID-19 were examined from 11 studies. The rate of hospitalization in the patients with liver cirrhosis was 17.6% (95% confidence interval [CI], 9%-44%). The rate of fever in the patients with liver cirrhosis was 4.5% (95% CI, 0.9%-8.1%). The rate of positive neutralizing antibodies in the patients with liver cirrhosis was 82.5% (95% CI, 69.8%-95.1%). Also, the rates of seroconversion after the second vaccination in patients with liver cirrhosis and the control group were 96.6% (95% CI, 92.0%-99.0%), and 99.7% (95% CI, 99.0%-100.0%), respectively. COVID-19 vaccines have demonstrated promising efficacy, immunogenicity, and safety profiles in individuals with liver cirrhosis, providing crucial protection against COVID-19-related complications.

The duty of care and the right to be cared for: is there a duty to treat the unvaccinated?

Vaccine hesitancy or refusal has been one of the major obstacles to herd immunity against Covid-19 in high-income countries and one of the causes for the emergence of variants. The refusal of people who are eligible for vaccination to receive vaccination creates an ethical dilemma between the duty of healthcare professionals (HCPs) to care for patients and their right to be taken care of. This paper argues for an extended social contract between patients and society wherein vaccination against Covid-19 is conceived as essential for the protection of the right of healthcare providers to be taken care of. Thus, a duty of care is only valid when those who can receive vaccination actually receive it. Whenever that is not the case, the continuing functioning of HCPs can only be perceived as supererogatory and not obligatory.

Immunogenicity phase II study evaluating booster capacity of nonadjuvanted AKS-452 SARS-Cov-2 RBD Fc vaccine

AKS-452, a subunit vaccine comprising an Fc fusion of the ancestral wild-type (WT) SARS-CoV-2 virus spike protein receptor binding domain (SP/RBD), was evaluated without adjuvant in a single cohort, non-randomized, open-labelled phase II study (NCT05124483) at a single site in The Netherlands for safety and immunogenicity. A single 90 µg subcutaneous booster dose of AKS-452 was administered to 71 adults previously primed with a registered mRNA- or adenovirus-based vaccine and evaluated for 273 days. All AEs were mild and no SAEs were attributable to AKS-452. While all subjects showed pre-existing SP/RBD binding and ACE2-inhibitory IgG titers, 60-68% responded to AKS-452 via ≥2-fold increase from days 28 to 90 and progressively decreased back to baseline by day 180 (days 28 and 90 mean fold-increases, 14.7 ± 6.3 and 8.0 ± 2.2). Similar response kinetics against RBD mutant proteins (including omicrons) were observed but with slightly reduced titers relative to WT. There was an expected strong inverse correlation between day-0 titers and the fold-increase in titers at day 28. AKS-452 enhanced neutralization potency against live virus, consistent with IgG titers. Nucleocapsid protein (Np) titers suggested infection occurred in 66% (46 of 70) of subjects, in which only 20 reported mild symptomatic COVID-19. These favorable safety and immunogenicity profiles support booster evaluation in a planned phase III universal booster study of this room-temperature stable vaccine that can be rapidly and inexpensively manufactured to serve vaccination at a global scale without the need of a complex distribution or cold chain.

Immune-mediated diseases after vaccinations with AZD1222, BNT-162b2, &/or mRNA-1273: An observational investigation of 78 patients

BACKGROUND

Immune-mediated diseases (IMDs) after nucleic acid-based vaccines have been sporadically reported since their introduction during the worldwide COVID-19 crisis. Confirming their cause-effect association remains challenging. We analysed the effects of AZD1222 (ChAdOx1 nCoV-19), BNT-162b2, and/or mRNA-1273 on the development &/or deterioration of IMDs in terms of the time of clinical onsets of IMDs after exposure to these vaccines.

METHODS

We retrospectively reviewed 78 in-patients in Taipei Veterans General Hospital, who presented with IMDs within 120 days after receiving AZD1222, BNT-162b2, &/or mRNA-1273 vaccinations in Taiwan from May 2021 to April 2022. The duration from inoculation to development of IMD was analysed by two-tailed Kolmogorov-Smirnov (K-S) test for goodness of fit.

RESULTS

The average time to new IMDs or flare-up of the diseases following vaccinations was 36 ± 26 days for all 91 events in these 78 patients. The onset time of IMDs after vaccinations was not haphazard as analysed by two-tailed K-S test for overall 91 events (40 new and 51 deteriorating episodes, p < 0.001). The IMDs presenting as non-connective tissue diseases (non-CTDs) have a shorter duration of incubation after vaccinations than those of CTDs (<14.7 days, 95 % confidence interval [CI], 3.0 to 26.4, p = 0.014). Furthermore, systemic vasculitis and type 2 inflammatory diseases were observed exclusively in those receiving AZD1222.

CONCLUSION

AZD1222, BNT-162b2, or mRNA-1273 influence the activities of IMDs in ways yet to be explored. High index of suspicion to IMDs after nucleic acid-based vaccine inoculation against COVID-19 may be important for primary care physicians.

Adverse Effects Post COVID-19 Vaccination and its Association with Age, Gender and Comorbid Disease in Basrah City Southern of Iraq

BACKGROUND

Vaccination against COVID-19 virus is the most valuable tool available for protection during the pandemic of coronavirus. The clinical manifestation post-vaccination is a barrier to vaccination for many people in Iraq and worldwide.

OBJECTIVES

The objective of this study is identifying various clinical manifestations occurring after receiving vaccines among individuals in Basrah Governorate. Moreover, we examine its association with respondents' demographics and the type of vaccine they received.

METHODS

A cross-section study was conducted in Basrah, southern Iraq. Research data were collected through an online questionnaire. The data were analyzed using both descriptive and analytic statistical tools using the SPSS program.

RESULTS

Most of the participants (86.68%) received the vaccine. The side effects were reported in 71.61% of vaccinated individuals. Fever and muscle pain were the two most experienced clinical manifestations, while lymph node enlargement and disturbances in taste and/or smell sensations were reported infrequently. Adverse effects were mostly reported with the Pfizer BioNTech vaccine receiver. Females and those in the younger age group also reported a significantly higher incidence of side effects.

CONCLUSION

Most adverse effects related to the COVID-19 vaccine were minor and could be tolerated without the need for hospital admission.

Vaccination to Reduce Antimicrobial Resistance Burden-Data Gaps and Future Research

Antimicrobial resistance (AMR) poses an immediate danger to global health. If unaddressed, the current upsurge in AMR threatens to reverse the achievements in reducing the infectious disease-associated mortality and morbidity associated with antimicrobial treatment. Consequently, there is an urgent need for strategies to prevent or slow the progress of AMR. Vaccines potentially contribute both directly and indirectly to combating AMR. Modeling studies have indicated significant gains from vaccination in reducing AMR burdens for specific pathogens, reducing mortality/morbidity, and economic loss. However, quantifying the real impact of vaccines in these reductions is challenging because many of the study designs used to evaluate the contribution of vaccination programs are affected by significant background confounding, and potential selection and information bias. Here, we discuss challenges in assessing vaccine impact to reduce AMR burdens and suggest potential approaches for vaccine impact evaluation nested in vaccine trials.

Occurrence and Risk Factors of Relapse Activity after Vaccination against COVID-19 in People with Multiple Sclerosis: 1-Year Follow-Up Results from a Nationwide Longitudinal Observational Study

Several studies reported post-SARS-CoV-2-vaccination (PV) symptoms. Even people with multiple sclerosis (PwMS) have concerns about disease activity following the SARS-CoV-2 vaccination. We aimed to determine the proportion of PwMS with PV relapses, the PV annualized relapse rate (ARR), the time from vaccination to subsequent relapses, and identify sociodemographic/clinical risk factors for PV relapses. PwMS were surveyed several times at baseline and four follow-ups as part of a longitudinal observational study regarding the safety and tolerability of the SARS-CoV-2 vaccination. The inclusion criteria for this analysis were age ≥18 years, ≥1 SARS-CoV-2 vaccination, and ≥1-year observation period since initial vaccination. Of 2466 PwMS, 13.8% reported PV relapses (mostly after second [N = 147] or booster vaccination [N = 145]) at a median of 8.0 (first/third quantile: 3.55/18.1) weeks PV, with the shortest period following initial vaccination (3.95 weeks). The ARR was 0.153 (95% confidence interval: 0.138-0.168), with a median observation period since initial vaccination of 1.2 years. Risk factors for PV relapses were younger age, female gender, moderate-severe disability levels, concurrent autoimmune diseases, relapsing-remitting MS courses, no DMT, and relapses within the year prior to the first vaccination. Patients' health conditions before/during initial vaccination may play a more important role in PV relapse occurrence than vaccination per se.

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.

Novel COVID-19 vaccine hesitancy and acceptance, and associated factors, amongst medical students: a scoping review

Medical students are likely to be exposed to COVID-19 patients so achieving high vaccination coverage rates for this group of healthcare workers is important, as is their potential as vaccination role models. The aim of this scoping review was to evaluate the current literature to determine the rates of COVID-19 vaccine hesitancy and acceptance, and associated factors, amongst medical students. Systematic searches of the Medline Ovid, Embase, PubMed, and Education Resources Information Centre (ERIC) online databases was conducted for relevant articles with keywords: 'COVID-19', 'vaccine hesitancy & acceptance' and 'medical students'. Articles were included for review if they reported the rates of vaccine hesitancy and acceptance, and associated factors, amongst medical students. Of the 258 articles identified, 52 met the inclusion criteria and underwent full-text review. Rates of vaccine hesitancy ranged from 5.4-86.7%, with generally positive attitudes towards COVID-19 vaccination. The main factors associated with vaccine hesitancy were concerns about the safety and efficacy of vaccines due to their accelerated development, being a pre-clinical medical student, and low perceived personal risk of COVID-19 infection. Inconsistencies were found for the influence of gender on attitudes towards vaccinations. Previous vaccination behaviours were predictive of willingness to receive the COVID-19 vaccine. Knowledge about COVID-19 vaccinations and their importance was found to be deficient amongst vaccine hesitant medical students. Generally, medical students express low levels of vaccine hesitancy. However, due to the variability in the factors associated with vaccine hesitancy across different populations and the dynamic and contextual nature of hesitancy, it is recommended that vaccination intent and associated attitudes are monitored on a longitudinal basis. It is important to map vaccine hesitancy at a local level to allow medical schools to develop strategies to encourage vaccination specific to their school's needs.

Side effects of COVID-19 vaccines in the middle eastern population

The COVID-19 pandemic has caused severe worldwide health concerns since its first description as the SARS-COV-2 virus in December 2019. The wide dissemination of this virus, together with the lack of treatment, prompted vaccine development within a short period of time to elicit a protective immunity against COVID-19. Due to their rapid development, potential subsequent side effects of COVID-19 vaccines were overlooked, which might lead to many health concerns. This is especially true for patients at a greater risk of harm from COVID-19, such as pregnant women, children, and patients with pre-existing chronic diseases. In this review, we provide a summary of common to rare side effects of administrated COVID-19 vaccines in a Middle Eastern population. We have found that the distinction between side effects from COVID-19 vaccines in terms of frequency and severity is attributed to the differences in study populations, gender, and age. Pain at the injection site, fever, headache, fatigue, and muscle pain were the most common reported side effects. Vaccinated subjects with previous COVID-19 infection exhibited an equivalent neutralizing response after just one dose compared to two doses of vaccine. Consequently, individuals who experienced more side effects had significantly higher antibody levels. This indicates that having better immunity correlates with higher antibody levels, leading to a higher frequency of vaccine side effects. Individuals with underlying comorbidities, particularly having known allergies and with illnesses such as diabetes and cancer, might be more prone to post-vaccination side effects. Studies of a high-risk population in Middle Eastern countries are limited. Future studies should be considered to determine long-term side effects, side effects after booster doses, and side effect differences in cases of heterologous and homologous vaccination for better understanding and proper handling of high-risk populations and patients who experience these side effects.

Some common deleterious mutations are shared in SARS-CoV-2 genomes from deceased COVID-19 patients across continents

The identification of deleterious mutations in different variants of SARS-CoV-2 and their roles in the morbidity of COVID-19 patients has yet to be thoroughly investigated. To unravel the spectrum of mutations and their effects within SARS-CoV-2 genomes, we analyzed 5,724 complete genomes from deceased COVID-19 patients sourced from the GISAID database. This analysis was conducted using the Nextstrain platform, applying a generalized time-reversible model for evolutionary phylogeny. These genomes were compared to the reference strain (hCoV-19/Wuhan/WIV04/2019) using MAFFT v7.470. Our findings revealed that SARS-CoV-2 genomes from deceased individuals belonged to 21 Nextstrain clades, with clade 20I (Alpha variant) being the most predominant, followed by clade 20H (Beta variant) and clade 20J (Gamma variant). The majority of SARS-CoV-2 genomes from deceased patients (33.4%) were sequenced in North America, while the lowest percentage (0.98%) came from Africa. The 'G' clade was dominant in the SARS-CoV-2 genomes of Asian, African, and North American regions, while the 'GRY' clade prevailed in Europe. In our analysis, we identified 35,799 nucleotide (NT) mutations throughout the genome, with the highest frequency (11,402 occurrences) found in the spike protein. Notably, we observed 4150 point-specific amino acid (AA) mutations in SARS-CoV-2 genomes, with D614G (20%) and N501Y (14%) identified as the top two deleterious mutations in the spike protein on a global scale. Furthermore, we detected five common deleterious AA mutations, including G18V, W45S, I33T, P30L, and Q418H, which play a key role in defining each clade of SARS-CoV-2. Our novel findings hold potential value for genomic surveillance, enabling the monitoring of the evolving pattern of SARS-CoV-2 infection, its emerging variants, and their impact on the development of effective vaccination and control strategies.

Background rates of adverse events of special interest for COVID-19 vaccines: A multinational Global Vaccine Data Network (GVDN) analysis

BACKGROUND

The Global COVID Vaccine Safety (GCoVS) project was established in 2021 under the multinational Global Vaccine Data Network (GVDN) consortium to facilitate the rapid assessment of the safety of newly introduced vaccines. This study analyzed data from GVDN member sites on the background incidence rates of conditions designated as adverse events of special interest (AESI) for COVID-19 vaccine safety monitoring.

METHODS

Eleven GVDN global sites obtained data from national or regional healthcare databases using standardized methods. Incident events of 13 pre-defined AESI were included for a pre-pandemic period (2015-19) and the first pandemic year (2020). Background incidence rates (IR) and 95% confidence intervals (CI) were calculated for inpatient and emergency department encounters, stratified by age and sex, and compared between pre-pandemic and pandemic periods using incidence rate ratios.

RESULTS

An estimated 197 million people contributed 1,189,652,926 person-years of follow-up time. Among inpatients in the pre-pandemic period (2015-19), generalized seizures were the most common neurological AESI (IR ranged from 22.15 [95% CI 19.01-25.65] to 278.82 [278.20-279.44] per 100,000 person-years); acute disseminated encephalomyelitis was the least common (<0.5 per 100,000 person-years at most sites). Pulmonary embolism was the most common thrombotic event (IR 45.34 [95% CI 44.85-45.84] to 93.77 [95% CI 93.46-94.08] per 100,000 person-years). The IR of myocarditis ranged from 1.60 [(95% CI 1.45-1.76) to 7.76 (95% CI 7.46-8.08) per 100,000 person-years. The IR of several AESI varied by site, healthcare setting, age and sex. The IR of some AESI were notably different in 2020 compared to 2015-19.

CONCLUSION

Background incidence of AESIs exhibited some variability across study sites and between pre-pandemic and pandemic periods. These findings will contribute to global vaccine safety surveillance and research.

Impact of COVID-19 Vaccinations on Menstrual Bleeding

INTRODUCTION

Vaccination has a fundamental role in protecting against and modifying the severity of several infectious diseases, including COVID-19. Several immune and non-immune adverse events have been reported post-COVID-19 vaccine. The aim of this study was to assess the effect of the COVID-19 vaccine on women's menstrual bleeding.

METHODS

A cross-sectional study was conducted among 399 vaccinated women in the Eastern Province of Saudi Arabia. Data were collected using a direct interview-based questionnaire including four sections.

RESULTS

A total of 399 women were recruited, with a mean age of 25.54 ± 6.177 years. More than half (53.9%) of the participants reported post-vaccination menstrual bleeding abnormality in terms of a heavy or irregular cycle. Out of the total number, 40 (21.4%) women reported having heavy menstrual flow, and 67 (16.8%) had non-menstrual bleeding after receiving the COVID-19 vaccine. Fully vaccinated women were at a greater risk of post-vaccination menstrual bleeding abnormality (p = 0.058). However, there was no correlation between booster shot type and menstrual bleeding abnormality (p > 0.05). In addition, there was no significant association between non-menstrual bleeding and the type of booster shot, the type of the first dose, and prior history of COVID-19 infection (p > 0.05).

CONCLUSION

Despite vaccination being the most effective way to prevent COVID-19, it does have an impact on menstrual bleeding in terms of menorrhagia and metrorrhagia. Therefore, more studies are needed to understand the mechanism and the long-term impact of COVID-19 vaccines on the hemostatic system.

Different Safety Pattern of an Inactivated SARS-CoV-2 Vaccine (CoronaVac®) According to Age Group in a Pediatric Population from 3 to 17 Years Old, in an Open-Label Study in Chile

During the COVID-19 pandemic, the importance of vaccinating children against SARS-CoV-2 was rapidly established. This study describes the safety of CoronaVac® in children and adolescents between 3- and 17-years-old in a multicenter study in Chile with two vaccine doses in a 4-week interval. For all participants, immediate adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs) were registered throughout the study. In the safety subgroup, AEs were recorded 28 days after each dose. COVID-19 surveillance was performed throughout the study. A total of 1139 individuals received the first and 1102 the second dose of CoronaVac®; 835 were in the safety subgroup. The first dose showed the highest number of AEs: up to 22.2% of participants reported any local and 17.1% systemic AE. AEs were more frequent in adolescents after the first dose, were transient, and mainly mild. Pain at the inoculation site was the most frequent AE for all ages. Fever was the most frequent systemic AE for 3-5 years old and headache in 6-17 years old. No SAEs or AESIs related to vaccination occurred. Most of the COVID-19 cases were mild and managed as outpatients. CoronaVac® was safe and well tolerated in children and adolescents, with different safety patterns according to age.

COVID-19 Vaccines over Three Years after the Outbreak of the COVID-19 Epidemic

The outbreak of COVID-19 started in December 2019 and spread rapidly all over the world. It became clear that the development of an effective vaccine was the only way to stop the pandemic. It was the first time in the history of infectious diseases that the process of the development of a new vaccine was conducted on such a large scale and accelerated so rapidly. At the end of 2020, the first COVID-19 vaccines were approved for marketing. At the end of March 2023, over three years after the outbreak of the COVID-19 pandemic, 199 vaccines were in pre-clinical development and 183 in clinical development. The candidate vaccines in the clinical phase are based on the following platforms: protein subunit, DNA, RNA, non-replication viral vector, replicating viral vector, inactivated virus, virus-like particles, live attenuated virus, replicating viral vector combined with an antigen-presenting cell, non-replication viral vector combined with an antigen-presenting cell, and bacterial antigen-spore expression vector. Some of the new vaccine platforms have been approved for the first time for human application. This review presents COVID-19 vaccines currently available in the world, procedures for assurance of the quality and safety of the vaccines, the vaccinated population, as well as future perspectives for the new vaccine platforms in drug and therapy development for infectious and non-infectious diseases.

Safety profile of inactivated COVID-19 vaccine in indonesian adults

Background

Vaccines are urgently needed to handle the morbidity and mortality of the COVID-19 pandemic in Indonesia. The inactivated vaccine is widely used in Indonesia's national immunization program due to its eligibility of stock, easier to transport, and considered to be more established than newer platforms. In this study, we aimed to evaluate the safety profile of the inactivated vaccine and analyze the safety profile between adults and the elderly.

Methods

A prospective analytical study was conducted to evaluate the safety profile of inactivated COVID-19 vaccine among healthy adults aged ≥ 18 years from September 2nd to December 28th, 2021, at ten primary health centers from 5 districts in Jakarta, Indonesia. The participants were instructed to record the symptoms after inactivated COVID-19 vaccine injection in the diary card for 28 days. Chi-square tests were carried out to analyze the relationship between the adverse event following immunization (AEFI) in adults and elderly groups.

Results

Four of 1113 participants were not included in this study due to the lack of follow-up. Out of 1109 participants, there were 1044 adults (18-59 years) and 65 elderly (>59 years). There were no serious AEFI cases reported. Most AEFI cases were mild to moderate and resolved after several days of injection. Local pain, myalgia and fatigue were the most frequent adverse events reported. We found that there was no correlation between the adults and elderly age group with the incidence of AEFI (p = 0.924) for local reactions (p = 0.181) and most of the systemic reactions (p = 0.629). However, there is an increased risk of fever in the elderly group compared to the adult group (OR 4.046, 95 % CI 1.794-9.124, p = 0.003) following immunization.

Conclusions

Our study demonstrated that the inactivated COVID-19 vaccine is safe, considering that all symptoms experienced were mild to moderate and resolved entirely.

Self-reported symptoms after COVID-19 vaccination. Distinct sex, age, and geographical outcomes in Lebanese and Italian cohorts

Following the COVID-19 discovery in December 2019, different vaccines were authorized in 2021 in Italy and Lebanon, but side effects and the impact of sex and age remained partly explored. We designed a web-based "Google Form" questionnaire to record self-reported systemic and local side effects up to 7 days after 1st and 2nd dose of the vaccine in two distinct Italian and Lebanese cohorts. Twenty-one questions in Italian and Arabic languages explored the prevalence and severity of 13 symptoms. Results were compared with respect to living country, timing, sex, and age classes. A total of 1,975 Italian subjects (age 42.9 ± SD16.8 years; 64.5% females) and 822 Lebanese subjects (age 32.5 ± SD15.9 years; 48.8% females) joined the study. The most common symptoms in both groups were injection site pain, weakness, and headache after the 1st and 2nd doses. The rate of post-vaccinal symptoms and the severity score were significantly higher in females than in males and progressively decreased with increasing age following both doses. We find that among two populations from the Mediterranean basin, the anti-COVID-19 vaccine generates mild age and sex-dependent adverse effects, with ethnic differences and prevalent symptoms rate and severity in females.

Dynamic Trends and Underlying Factors of COVID-19 Vaccine Booster Hesitancy in Adults: Cross-Sectional Observational Study

BACKGROUND

COVID-19 vaccine hesitancy reduces vaccination rates, which is detrimental to building herd immunity and halting the spread of COVID-19 and its variations. Most researches have simply identified the reasons affecting COVID-19 vaccination reluctance without delving into its dynamics, which makes forecasting future trends difficult.

OBJECTIVE

This study aimed to examine the current COVID-19 vaccine booster hesitancy rate in Chinese adults as well as the dynamics of vaccine hesitancy and its influencing factors. The results of this study will have practical implications for policy responses in mainland China, and effective COVID-19 booster vaccination in specific populations.

METHODS

The web-based survey was completed by creating questionnaires and using a stratified random sampling method to collect information from adults (≥18 years old) among 2556 households in 4 geographical regions of China. We collected sociodemographic information, health status, awareness of COVID-19 and its vaccine, self-perceptions, trust in medical staff and vaccine developers, and so on. The odds ratios and 95% CI for the statistical associations were estimated using logistic regression models.

RESULTS

Overall, 6659 participants (females: n=3540, 53.2%; males: n=3119, 46.8%) responded. In total, 533 (8%; 95% CI 7.4%-8.7%) participants presented a clear hesitancy in receiving the COVID-19 booster vaccination, while 736 (11.1%; 95% CI 10.3%-11.8%) expressed hesitancy in regular booster vaccination. A higher prevalence of vaccine hesitancy in both booster vaccination and regular booster vaccination was observed among participants with a history of allergies, experiencing chronic disease, lower levels of public health prevention measures or susceptibility or benefits or self-efficiency, higher levels of severity or barriers, and lower trust in both medical staff and vaccine developers (P<.05). The females and participants with higher education levels, higher levels of barriers, lower levels of susceptibility, and lower trust in vaccine developers preferred to have attitudinal changes from acceptance to hesitancy, while people with higher education levels, lower self-report health conditions, experiencing chronic disease, history of allergies, and lower trust in medical staff and developers were all positively associated with constant COVID-19 booster hesitancy.

CONCLUSIONS

The prevalence of COVID-19 vaccine booster hesitancy is not high in mainland China. However, there is a slight increment in hesitancy on regular booster vaccination. Conducting targeted information guidance for people with higher education levels and chronic diseases, as well as improving accessibility to booster vaccination and increasing trust in medical staff and vaccine producers may be highly effective in reducing vaccine hesitancy.

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.

The evolution of COVID-19 vaccine hesitancy in Sub-Saharan Africa: evidence from panel survey data

BACKGROUND

COVID-19 vaccination efforts are lagging in Sub-Saharan Africa, as just over 20 percent of the population has been fully vaccinated. COVID-19 vaccine hesitancy is considered important as a prerequisite for widespread vaccine take-up. Here, we study the dynamics of vaccine acceptance, its correlates, and reasons for hesitancy over time, drawing on two years of panel survey data.

METHODS

In this observational study, we use multiple rounds of data from national High Frequency Phone Surveys (HFPS) in five countries in East and West Africa (Burkina Faso, Ethiopia, Malawi, Nigeria, and Uganda), covering a period between 2020 and 2022. The surveys are cross-country comparable and draw their samples from nationally representative sampling frames. Based on this data source, the study presents population-weighted means and performs multivariate regression analysis.

RESULTS

COVID-19 vaccine acceptance was high throughout the study period (68% to 98%). However, acceptance levels were lower in 2022 than in 2020 in three countries (Burkina Faso, Malawi, Nigeria), and higher in one country (Uganda). Moreover, individuals are observed to change their stated vaccine attitudes between survey rounds, to a limited extent in some countries (Ethiopia) and more frequently in others (Burkina Faso, Malawi, Nigeria, Uganda). Vaccine hesitancy is higher in richer households, and those residing in urban areas; among women and those better educated. Hesitancy is lower in larger households and among heads of the household. The main reasons for hesitancy are concerns about side effects of the vaccine, its safety and efficacy, as well as assessments of COVID-19 risk, though these reasons fluctuate over time.

CONCLUSIONS

Reported COVID-19 vaccine acceptance levels remain far above vaccination rates in the study countries, suggesting that vaccine hesitancy is not the primary obstacle to reaching greater vaccine coverage, which may instead be related to access and delivery barriers as well as supply shortages. Nevertheless, vaccine attitudes appear malleable so that continued efforts are needed to retain high levels of vaccine acceptance.

Treatment mechanism of immune triad from the repurposing drug against COVID-19

COVID-19 is an immune-mediated disease whose pathophysiology uses SAMHD1 tetramerization and cGAS-STING signaling, toll-like receptor 4 (TLR4) cascade, spike protein- inflammasome activation, and neuropilin 1 (NRP1) signaling. Variants of concern, such as SARS-CoV-2 Omicron Subvariants BQ.1, BQ.1.1, BA.4.6, BF.7, BA.2.75.2, and other mutants, have emerged. The longitudinal memory T-cell response to SARS-CoV-2 persists for eight months after symptom onset. Therefore, we must achieve viral clearance to coordinate immune cell reactions. Aspirin, dapsone, and dexamethasone as anticatalysis medicines have been used to treat COVID-19. They are shown to work harmoniously with modulating ILCs. Therefore, it needs to prescribe this immune triad to alleviate the clinical pathologic course and block exacerbation mechanisms due to diverse SARS-CoV-2 variants.

Long-lasting neutralizing antibodies and T cell response after the third dose of mRNA anti-SARS-CoV-2 vaccine in multiple sclerosis

Background and objectives

Long lasting immune response to anti-SARS-CoV-2 vaccination in people with Multiple Sclerosis (pwMS) is still largely unexplored. Our study aimed at evaluating the persistence of the elicited amount of neutralizing antibodies (Ab), their activity and T cell response after three doses of anti-SARS-CoV-2 vaccine in pwMS.

Methods

We performed a prospective observational study in pwMS undergoing SARS-CoV-2 mRNA vaccinations. Anti-Region Binding Domain (anti-RBD) of the spike (S) protein immunoglobulin G (IgG) titers were measured by ELISA. The neutralization efficacy of collected sera was measured by SARS-CoV-2 pseudovirion-based neutralization assay. The frequency of Spike-specific IFNγ-producing CD4+ and CD8+ T cells was measured by stimulating Peripheral Blood Mononuclear Cells (PBMCs) with a pool of peptides covering the complete protein coding sequence of the SARS-CoV-2 S.

Results

Blood samples from 70 pwMS (11 untreated pwMS, 11 under dimethyl fumarate, 9 under interferon-γ, 6 under alemtuzumab, 8 under cladribine, 12 under fingolimod and 13 under ocrelizumab) and 24 healthy donors were collected before and up to six months after three vaccine doses. Overall, anti-SARS-CoV-2 mRNA vaccine elicited comparable levels of anti-RBD IgGs, neutralizing activity and anti-S T cell response both in untreated, treated pwMS and HD that last six months after vaccination. An exception was represented by ocrelizumab-treated pwMS that showed reduced levels of IgGs (p<0.0001) and a neutralizing activity under the limit of detection (p<0.001) compared to untreated pwMS. Considering the occurrence of a SARS-CoV-2 infection after vaccination, the Ab neutralizing efficacy (p=0.04), as well as CD4+ (p=0.016) and CD8+ (p=0.04) S-specific T cells, increased in treated COVID+ pwMS compared to uninfected treated pwMS at 6 months after vaccination.

Discussion

Our follow-up provides a detailed evaluation of Ab, especially in terms of neutralizing activity, and T cell responses after anti-SARS-CoV-2 vaccination in MS context, over time, considering a wide number of therapies, and eventually breakthrough infection. Altogether, our observations highlight the vaccine response data to current protocols in pwMS and underline the necessity to carefully follow-up anti-CD20- treated patients for higher risk of breakthrough infections. Our study may provide useful information to refine future vaccination strategies in pwMS.

Real-World Safety of COVID-19 mRNA Vaccines: A Systematic Review and Meta-Analysis

With the mass vaccination program for COVID-19 mRNA vaccines, there has been sufficient real-world study (RWS) on the topic to summarize their safety in the total population and in immunocompromised (IC) patients who were excluded from phase 3 clinical trials. We conducted a systematic review and meta-analysis to evaluate the safety of COVID-19 mRNA vaccines, with a total of 5,132,799 subjects from 122 articles. In the case of the total population vaccinated with first, second, and third doses, the pooled incidence of any adverse events (AEs) was 62.20%, 70.39%, and 58.60%; that of any local AEs was 52.03%, 47.99%, and 65.00%; that of any systemic AEs was 29.07%, 47.86%, and 32.71%. Among the immunocompromised patients, the pooled odds ratio of any AEs, any local AEs, and systemic AEs were slightly lower than or similar to those of the healthy controls at 0.60 (95% CI: 0.33-1.11), 0.19 (95% CI: 0.10-0.37), and 0.36 (95% CI: 0.25-0.54), with pooled incidences of 51.95%, 38.82%, and 31.00%, respectively. The spectrum of AEs associated with the vaccines was broad, but most AEs were transient, self-limiting, and mild to moderate. Moreover, younger adults, women, and people with prior SARS-CoV-2 infection were more likely to experience AEs.

Production of a promising modular proteinaceous self-assembled delivery system for vaccination

Recently, there have been enormous advances in nano-delivery materials, especially safer and more biocompatible protein-based nanoparticles. Generally, proteinaceous nanoparticles (such as ferritin and virus-like particles) are self-assembled from some natural protein monomers. However, to ensure their capability of assembly, it is difficult to upgrade the protein structure through major modifications. Here, we have developed an efficient orthogonal modular proteinaceous self-assembly delivery system that could load antigens with an attractive coupling strategy. In brief, we constructed a nanocarrier by fusing two orthogonal domains-a pentameric cholera toxin B subunit and a trimer forming peptide-and an engineered streptavidin monomer for binding biotinylated antigens. After successfully preparing the nanoparticles, the receptor-binding domain of SARS-CoV-2 spike protein and influenza virus haemagglutination antigen are used as model antigens for further evaluation. We found that the biotinylated antigen is able to bind to the nanoparticles with high affinity and achieve efficient lymph node drainage when loaded on the nanoparticles. Then, T cells are greatly activated and the formation of germinal centers is observed. Experiments of two mouse models demonstrate the strong antibody responses and prophylactic effects of these nanovaccines. Thus, we establish a proof-of-concept for the delivery system with the potential to load diverse antigen cargos to generate high-performance nanovaccines, thereby offering an attractive platform technology for nanovaccine preparation.

Licenced doses of approved COVID-19 vaccines may not be optimal: A review of the early-phase, dose-finding trials

Although over 13 billion COVID-19 vaccine doses have been administered globally, the issue of whether the optimal doses are being used has received little attention. To address this question we reviewed the reports of early-phase dose-finding trials of the nine COVID-19 vaccines approved by World Health Organization, extracting information on study design and findings on reactogenicity and early humoral immune response. The number of different doses evaluated for each vaccine varied widely (range 1-7), as did the number of subjects studied per dose (range 15-190). As expected, the frequency and severity of adverse reactions generally increased at higher doses, although most were clinically tolerable. Higher doses also tended to elicit better immune responses, but differences between the highest dose and the second-highest dose evaluated were small, typically less than 1.6-fold for both binding antibody concentration and neutralising antibody titre. All of the trials had at least one important design limitation - few doses evaluated, large gaps between adjacent doses, or an inadequate sample size - although this is not a criticism of the study investigators, who were working under intense time pressures at the start of the epidemic. It is therefore open to question whether the single dose taken into clinical efficacy trials, and subsequently authorised by regulatory agencies, was optimal. In particular, our analysis indicates that the recommended doses for some vaccines appear to be unnecessarily high. Although reduced dosing for booster injections is an active area of research, the priming dose also merits study. We conclude by suggesting improvements in the design of future vaccine trials, for both next-generation COVID-19 vaccines and for vaccines against other pathogens.

Understanding the challenges to COVID-19 vaccines and treatment options, herd immunity and probability of reinfection

Unlike pandemics in the past, the outbreak of coronavirus disease 2019 (COVID-19), which rapidly spread worldwide, was met with a different approach to control and measures implemented across affected countries. The lack of understanding of the fundamental nature of the outbreak continues to make COVID-19 challenging to manage for both healthcare practitioners and the scientific community. Challenges to vaccine development and evaluation, current therapeutic options, convalescent plasma therapy, herd immunity, and the emergence of reinfection and new variants remain the major obstacles to combating COVID-19. This review discusses these challenges in the management of COVID-19 at length and highlights the mechanisms needed to provide better understanding of this pandemic.

COVID-19 vaccine coverage, safety, and perceptions among patients with diabetes mellitus in China: a cross-sectional study

Aims

Diabetes mellitus (DM), one of the most common chronic diseases in China, is a risk factor for SARS-COV-2 infection and poor prognosis of COVID-19. The COVID-19 vaccine is one of the key measures to control the pandemic. However, the actual coverage of COVID-19 vaccination and associated factors remain unclear among DM patients in China. We conducted this study to investigate the COVID-19 vaccine coverage, safety, and perceptions among patients with DM in China.

Methods

A cross-sectional study of a sample of 2200 DM patients from 180 tertiary hospitals in China was performed using a questionnaire developed through the Wen Juan Xing survey platform to collect information regarding their coverage, safety, and perceptions of COVID-19 vaccination. A multinomial logistic regression analysis model was performed to determine any independent relationships with COVID-19 vaccination behavior among DM patients.

Results

In total, 1929 (87.7%) DM patients have received at least one dose COVID-19 vaccine, and 271 (12.3%) DM patients were unvaccinated. In addition, 65.2% (n = 1434) were booster vaccinated against COVID-19, while 16.2% (n = 357) were only fully vaccinated and 6.3% (n = 138) were only partially vaccinated. The prevalence of adverse effects after the first dose of vaccine, the second dose of vaccine, and the third dose of vaccine were 6.0%, 6.0%, and 4.3% respectively. Multinomial logistic regression analysis showed that DM patients complicated with immune and inflammatory diseases (partially vaccinated: OR = 0.12; fully vaccinated: OR = 0.11; booster vaccinated: OR = 0.28), diabetic nephropathy (partially vaccinated: OR = 0.23; fully vaccinated: OR = 0.50; booster vaccinated: OR = 0.30), and perceptions on the safety of COVID-19 vaccine (partially vaccinated: OR = 0.44; fully vaccinated: OR = 0.48; booster vaccinated: OR = 0.45) were all associated with the three of vaccination status.

Conclusion

This study showed that higher proportion of COVID-19 vaccine coverage among patients with DM in China. The concern about the safety of the COVID-19 vaccine affected the vaccine behavior in patients with DM. The COVID-19 vaccine was relatively safe for DM patients due to all side effects were self-limiting.

Can Risk Communication Surveillance Prompt COVID-19 Vaccine Acceptance among Internet users? Applying the Situational Theory of Problem Solving: A Cross-Sectional Study

BACKGROUND

The World Health Organization has recently raised concerns about the low number of fully vaccinated people against COVID-19 among developing countries. The low ratio of fully vaccinated people and the emergence of renewed infectious variants correspond to worsening public health. Global health managers have highlighted COVID-19 vaccine-related infodemics as the significant risk perception factor that hinders mass vaccination campaigns.

OBJECTIVE

Given the ambiguous digital communication environment which has fostered infodemics, developing nations struggle to boost public willingness to get people fully vaccinated. Authorities have launched some risk communication-laden digital interventions in response to infodemics. However, the value of these risk communication strategies employed to tackle infodemics needs to be evaluated. The current research using the tenets of the situational theory of problem-solving is novel, as it explores the impending effects of risk communication strategies. The relationship between infodemic-induced risk perception about COVID-19 vaccine safety and risk communication actions to intensify willingness to get fully vaccinated was examined.

METHODS

This research used a cross-sectional research design vis-à-vis nationally representative online survey. We collected data from 1946 internet users across Pakistan. Participants voluntarily participated in this research after filling consent form and reading the ethical permissions. Responses were received over three months, from May 2022 to July 2022.

RESULTS

The results delineated that infodemics positively affect risk perception. This realization pushed the public to engage in risky communicative actions through reliance on and search for accurate information. Therefore, the prospect of managing infodemics through risk information exposure (e.g., digital interventions) using the situational context could predict robust willingness to get fully vaccinated against COVID-19.

CONCLUSIONS

The pioneering results offer strategic considerations for health authorities to effectively man-age the descending spiral of optimal protection against COVID-19. This research concludes that the likelihood of managing infodemics using the situational context through exposure to relevant information could improve one's knowledge of forfending and selection, which can lead to robust protection against COVID-19. Hence, more situation-specific information about the underpinning problem (i.e., selection of appropriate vaccine) can be made accessible through several official digital sources to achieve a more active public health response.

Vaccine-induced immune thrombotic thrombocytopenia: what do we know hitherto?

Vaccine-induced immune thrombotic thrombocytopenia (VITT), also known as thrombosis with thrombocytopenia syndrome, is a catastrophic and life-threatening reaction to coronavirus disease 2019 (COVID-19) vaccines, which occurs disproportionately in response to vaccination with non-replicating adenovirus vector (AV) vaccines. The mechanism of VITT is not well defined and it has not been resolved why cases of VITT are predominated by vaccination with AV vaccines. However, virtually all VITT patients have positive platelet-activating anti-platelet factor 4 (PF4) antibody titers. Subsequently, platelets are activated and depleted in an Fcγ-receptor IIa (FcγRIIa or CD32a)-dependent manner, but it is not clear why or how the anti-PF4 response is mounted. This review describes the pathogenesis of VITT and provides insight into possible mechanisms that prompt the formation of a PF4/polyanion complex, which drives VITT pathology, as an amalgam of current experimental data or hypotheses.

Potential treatments of COVID-19: Drug repurposing and therapeutic interventions

The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infection is caused when Spike-protein (S-protein) present on the surface of SARS-CoV-2 interacts with human cell surface receptor, Angiotensin-converting enzyme 2 (ACE2). This binding facilitates SARS-CoV-2 genome entry into the human cells, which in turn causes infection. Since the beginning of the pandemic, many different therapies have been developed to combat COVID-19, including treatment and prevention. This review is focused on the currently adapted and certain other potential therapies for COVID-19 treatment, which include drug repurposing, vaccines and drug-free therapies. The efficacy of various treatment options is constantly being tested through clinical trials and in vivo studies before they are made medically available to the public.

Overview of the cardio-metabolic impact of the COVID-19 pandemic

Evidence has shown that cardiometabolic disorders (CMDs) are amongst the top contributors to COVID-19 infection morbidity and mortality. The reciprocal impact of COVID-19 infection and the most common CMDs, the risk factors for poor composite outcome among patients with one or several underlying diseases, the effect of common medical management on CMDs and their safety in the context of acute COVID-19 infection are reviewed. Later on, the changes brought by the COVID-19 pandemic quarantine on the general population's lifestyle (diet, exercise patterns) and metabolic health, acute cardiac complications of different COVID-19 vaccines and the effect of CMDs on the vaccine efficacy are discussed. Our review identified that the incidence of COVID-19 infection is higher among patients with underlying CMDs such as hypertension, diabetes, obesity and cardiovascular disease. Also, CMDs increase the risk of COVID-19 infection progression to severe disease phenotypes (e.g. hospital and/or ICU admission, use of mechanical ventilation). Lifestyle modification during COVID-19 era had a great impact on inducing and worsening of CMDs. Finally, the lower efficacy of COVID-19 vaccines was found in patients with metabolic disease.

COVID-19 Vaccine-Associated Pneumonitis in the Republic of Korea: A Nationwide Multicenter Survey

BACKGROUND

Recent reports have suggested that pneumonitis is a rare complication following vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, its clinical features and outcomes are not well known. The aim of this study was to identify the clinical characteristics and outcomes of patients with vaccine-associated pneumonitis following vaccination against SARS-CoV-2.

METHODS

In this nationwide multicenter survey study, questionnaires were distributed to pulmonary physicians in referral hospitals. They were asked to report cases of development or exacerbation of interstitial lung disease (ILD) associated with the coronavirus disease 2019 vaccine. Vaccine-associated pneumonitis was defined as new pulmonary infiltrates documented on chest computed tomography within 4 weeks of vaccination and exclusion of other possible etiologies.

RESULTS

From the survey, 49 cases of vaccine-associated pneumonitis were identified between February 27 and October 30, 2021. After multidisciplinary discussion, 46 cases were analyzed. The median age was 66 years and 28 (61%) were male. The median interval between vaccination and respiratory symptoms was 5 days. There were 20 (43%), 17 (37%), and nine (19%) patients with newly identified pneumonitis, exacerbation of pre-diagnosed ILD, and undetermined pre-existing ILD, respectively. The administered vaccines were BNT162b2 and ChAdOx1 nCov-19/AZD1222 each in 21 patients followed by mRNA-1273 in three, and Ad26.COV2.S in one patient. Except for five patients with mild disease, 41 (89%) patients were treated with corticosteroid. Significant improvement was observed in 26 (57%) patients including four patients who did not receive treatment. However, ILD aggravated in 9 (20%) patients despite treatment. Mortality was observed in eight (17%) patients.

CONCLUSION

These results suggest pneumonitis as a potentially significant safety concern for vaccines against SARS-CoV-2. Clinical awareness and patient education are necessary for early recognition and prompt management. Additional research is warranted to identify the epidemiology and characterize the pathophysiology of vaccine-associated pneumonitis.

Uptake of COVID-19 vaccination in people with blood cancer: Population-level cohort study of 12 million patients in England

BACKGROUND

People with blood cancers have increased risk of severe outcomes from COVID-19 and were prioritised for vaccination.

METHODS

Individuals in the QResearch database aged 12 years and above on 1st December 2020 were included in the analysis. Kaplan-Meier analysis described time to COVID-19 vaccine uptake in people with blood cancer and other high-risk disorders. Cox regression was used to identify factors associated with vaccine uptake in people with blood cancer.

RESULTS

The analysis included 12,274,948 individuals, of whom 97,707 had a blood cancer diagnosis. 92% of people with blood cancer received at least one dose of vaccine, compared to 80% of the general population, but there was lower uptake of each subsequent vaccine dose (31% for fourth dose). Vaccine uptake decreased with social deprivation (HR 0.72, 95% CI 0.70, 0.74 for most deprived versus most affluent quintile for first vaccine). Compared with White groups, uptake of all vaccine doses was significantly lower in people of Pakistani and Black ethnicity, and more people in these groups remain unvaccinated.

CONCLUSIONS

COVID-19 vaccine uptake declines following second dose and there are ethnic and social disparities in uptake in blood cancer populations. Enhanced communication of benefits of vaccination to these groups is needed.

Follow-Up of Side Effects throughout the Entire Course of Coronavirus Vaccination

Vaccines are considered the best protective means against coronavirus infection. There is increasing interest in reporting the side effects of vaccines, especially for individuals younger than 18 years old. Accordingly, this analytical cohort study aims to report on the side effects of adult and young individuals who received vaccination within 24 h, 72 h, 5 days, and 1 week through the entire course of vaccination (ECoV). A validated online survey was used to collect information. In total, 1069 individuals were completely followed. Most individuals received the Pfizer vaccine (59.6%). Most individuals had received two doses (69.4%). Very strong and statistically significant associations with side effects (p < 0.05, Phi (Φ) > 0.25) throughout the ECoV were reported for the type of vaccine and female gender. Non-smokers reported weak statistically significant associations. Fatigue and localized pain were the most commonly reported side effect, with onset within 24 h and duration of less than 72 h. The prevalence of reported side effects was statistically significantly higher among young individuals (<18 years old) than among adults (X2 (1) =7.6, p = 0.006. Phi φ = 0.11).

Post-truth epistemic beliefs rooted in the Dark Factor of Personality are associated with higher COVID-19 vaccination refusal

A substantial number of people refused to get vaccinated against COVID-19, which prompts the question as to why. We focus on the role of individual worldviews about the nature and generation of knowledge (epistemic beliefs). We propose a model that includes epistemic beliefs, their relationship to the Dark Factor of Personality (D), and their mutual effect on the probability of having been vaccinated against COVID-19. Based on a US nationally representative sample (N = 1268), we show that stronger endorsement of post-truth epistemic beliefs was associated with a lower probability of having been vaccinated against COVID-19. D was also linked to a lower probability of having been vaccinated against COVID-19, which can be explained by post-truth epistemic beliefs. Our results indicate that the more individuals deliberately refrain from adhering to the better argument, the less likely they are vaccinated. More generally, post-truth epistemic beliefs pose a challenge for rational communication.

A randomized phase I/II safety and immunogenicity study of the Montanide-adjuvanted SARS-CoV-2 spike protein-RBD-Fc vaccine, AKS-452

BACKGROUND

Previous interim data from a phase I study of AKS-452, a subunit vaccine comprising an Fc fusion of the respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein receptor binding domain (SP/RBD) emulsified in the water-in-oil adjuvant, Montanide™ ISA 720, suggested a good safety and immunogenicity profile in healthy adults. This phase I study was completed and two dosing regimens were further evaluated in this phase II study.

METHODS

This phase II randomized, open-labelled, parallel group study was conducted at a single site in The Netherlands with 52 healthy adults (18 - 72 years) receiving AKS-452 subcutaneously at one 90 µg dose (cohort 1, 26 subjects) or two 45 µg doses 28 days apart (cohort 2, 26 subjects). Serum samples were collected at the first dose (day 0) and at days 28, 56, 90, and 180. Safety and immunogenicity endpoints were assessed, along with induction of IgG isotypes, cross-reactive immunity against viral variants, and IFN-γ T cell responses.

RESULTS

All AEs were mild/moderate (grades 1 or 2), and no SAEs were attributable to AKS-452. Seroconversion rates reached 100% in both cohorts, although cohort 2 showed greater geometric mean IgG titers that were stable through day 180 and associated with enhanced potencies of SP/RBD-ACE2 binding inhibition and live virus neutralization. AKS-452-induced IgG titers strongly bound mutant SP/RBD from several SARS-CoV-2 variants (including Omicrons) that were predominantly of the favorable IgG1/3 isotype and IFN-γ-producing T cell phenotype.

CONCLUSION

These favorable safety and immunogenicity profiles of the candidate vaccine as demonstrated in this phase II study are consistent with those of the phase I study (ClinicalTrials.gov: NCT04681092) and suggest that a total of 90 µg received in 2 doses may offer a greater duration of cross-reactive neutralizing titers than when given in a single dose.

Adverse Events to SARS-CoV-2 (COVID-19) Vaccines and Policy Considerations that Inform the Funding of Safety Surveillance in Low- and Middle-Income Countries: A Mixed Methods Study

INTRODUCTION/OBJECTIVE

Rapid global approval of coronavirus disease 2019 (COVID-19) vaccines and concurrent introduction in high-income countries and low- and middle-income countries (LMIC) highlights the importance of equitable safety surveillance of adverse events following immunization (AEFIs). We profiled AEFIs to COVID-19 vaccines, explored reporting differences between Africa and the rest of the world (RoW), and analyzed policy considerations that inform strengthening of safety surveillance in LMICs.

METHODS

Using a convergent mixed-methods design we compared the rate and profile of COVID-19 vaccines' AEFIs reported to VigiBase by Africa versus the RoW, and interviewed policymakers to elicit considerations that inform the funding of safety surveillance in LMICs.

RESULTS

With 87,351 out of 14,671,586 AEFIs, Africa had the second-lowest crude number and a reporting rate of 180 adverse events (AEs) per million administered doses. Serious AEs (SAEs) were 27.0%. Death accounted for about 10.0% of SAEs. Significant differences were found in reporting by gender, age group, and SAEs between Africa and the RoW. AstraZeneca and Pfizer BioNTech vaccines were associated with a high absolute number of AEFIs for Africa and RoW; Sputnik V contributed a considerably high rate of AEs per 1 million administered doses. Funding decisions for safety surveillance in LMICs were not based on explicit policies but on country priorities, perceived utility of data, and practical implementation issues.

CONCLUSION

African countries reported fewer AEFIs relative to the RoW. To enhance Africa's contribution to the global knowledge on COVID-19 vaccine safety, governments must explicitly consider safety monitoring as a priority, and funding organizations need to systematically and continuously support these programs.

A 1-year analysis of adverse events following COVID-19 vaccination in Lebanon: a retrospective study

BACKGROUND

Since the deployment of Coronavirus Disease 2019 (COVID-19) vaccines, skepticism about the safety, incidence, and severity of Adverse Events Following Immunization (AEFI) was a concern. The study has two main objectives. First, to analyze AEFIs following COVID-19 vaccines (Pfizer-BioNTech, AstraZeneca, Sputnik, and Sinopharm) during the vaccination campaign in Lebanon and correlate them with age and gender. Second, to correlate Pfizer-BioNTech and AstraZeneca vaccines' AEFI with the dose administered.

METHODS

A retrospective study was carried out between February 14th, 2021, and February 14th, 2022. AEFI case reports received to the Lebanese Pharmacovigilance (PV) Program were cleaned, validated, and analyzed using SPSS software.

RESULTS

A total of 6808 AEFI case reports were received to the Lebanese PV Program during the period of this study. Case reports were mostly received from females (60.7%) and from vaccine recipients aged 18-44 years. As for the vaccine type, AEFIs occurred more frequently with the AstraZeneca vaccine compared to the Pfizer-BioNTech vaccine. The latter had AEFIs mainly following dose 2, whereas AEFIs with the AstraZeneca vaccine were more frequently reported after dose 1, with general body pain being the most reported systemic AEFI with PZ (34.6%), while fatigue was the most reported AEFI with AZ vaccine (56.5%).

CONCLUSIONS

The AEFI reported with COVID-19 vaccines in Lebanon were aligned with those reported worldwide. The incidence of rare serious AEFIs should not discourage the public from getting vaccinated. Further studies are needed to evaluate their long-term potential risk.

Using the precaution adoption process model to understand decision-making about the COVID-19 booster vaccine in England

BACKGROUND

COVID-19 continues to pose a threat to public health. Booster vaccine programmes are critical to maintain population-level immunity. Stage theory models of health behaviour can help our understanding of vaccine decision-making in the context of perceived threats of COVID-19.

PURPOSE

To use the Precaution Adoption Process Model (PAPM) to understand decision-making about the COVID-19 booster vaccine (CBV) in England.

METHODS

An online, cross-sectional survey informed by the PAPM, the extended Theory of Planned Behaviour and Health Belief Model administered to people over the age of 50 residing in England, UK in October 2021. A multivariate, multinomial logistic regression model was used to examine associations with the different stages of CBV decision-making.

RESULTS

Of the total 2,004 participants: 135 (6.7%) were unengaged with the CBV programme; 262 (13.1%) were undecided as to whether to have a CBV; 31 (1.5%) had decided not to have a CBV; 1,415 (70.6%) had decided to have a CBV; and 161 (8.0%) had already had their CBV. Being unengaged was positively associated with beliefs in their immune system to protect against COVID-19, being employed, and low household income; and negatively associated with CBV knowledge, a positive COVID-19 vaccine experience, subjective norms, anticipated regret of not having a CBV, and higher academic qualifications. Being undecided was positively associated with beliefs in their immune system and having previously received the Oxford/AstraZeneca (as opposed to Pfizer/BioNTech) vaccine; and negatively associated with CBV knowledge, positive attitudes regarding CBV, a positive COVID-19 vaccine experience, anticipated regret of not having a CBV, white British ethnicity, and living in East Midlands (vs London).

CONCLUSIONS

Public health interventions promoting CBV may improve uptake through tailored messaging directed towards the specific decision stage relating to having a COVID-19 booster.

Six-month safety follow-up of an adjuvanted SARS-CoV-2 trimeric S-protein subunit vaccine (SCB-2019) in adults: A phase 2/3, double-blind, randomized study

BACKGROUND

We evaluated the safety of SCB-2019, a protein subunit vaccine candidate containing a recombinant SARS-CoV-2 spike (S) trimer fusion protein, combined with CpG-1018/alum adjuvants.

METHODS

This ongoing phase 2/3, double-blind, placebo-controlled, randomized trial is being conducted in Belgium, Brazil, Colombia, the Philippines, and South Africa in participants ≥ 12 years of age. Participants were randomly assigned to receive 2 doses of SCB-2019 or placebo administered intramuscularly 21 days apart. Here, we present the safety results of SCB-2019 over the 6-month period following 2-dose primary vaccination series in all adult participants (≥18 years of age).

RESULTS

A total of 30,137 adult participants received at least one dose of study vaccine (n = 15,070) or placebo (n = 15,067) between 24 March 2021 and 01 December 2021. Unsolicited adverse events, medically-attended adverse events, adverse events of special interest, and serious adverse events were reported in similar frequencies in both study arms over the 6-month follow-up period. Vaccine-related SAEs were reported by 4 of 15,070 SCB-2019 recipients (hypersensitivity reactions in two participants, Bell's palsy, and spontaneous abortion) and 2 of 15,067 placebo recipients (COVID-19, pneumonia, and acute respiratory distress syndrome in one participant and spontaneous abortion in the other one). No signs of vaccine-associated enhanced disease were observed.

CONCLUSIONS

SCB-2019 administered as a 2-dose series has an acceptable safety profile. No safety concerns were identified during the 6-month follow-up after the primary vaccination.

CLINICAL TRIALS REGISTRATION

NCT04672395; EudraCT: 2020-004272-17.

Safety of primary immunization using inactivated SARS-CoV-2 vaccine (CoronaVac®) among population aged 3 years and older in a large-scale use: A multi-center open-label study in China

OBJECTIVE

To evaluate the safety of primary immunization using CoronaVac® among population aged 3 years and above in a large-scale use.

METHOD

A multi-center open-label study was carried out in 11 provinces of China. Individuals aged 3 years and older who had no history of COVID-19 vaccination or had received only one dose of CoronaVac® were enrolled in this study. Adults and elderly with or without underlying medical conditions(UMCs) were also recruited. Eligible participants received one or two doses of CoronaVac® with an interval of 28 days. Demographic information, vaccination and the occurrence of adverse events were recorded by participants or guardians using data collection system designed for this study. All adverse events occurred within 6 months after the second dose of vaccination were collected. The incidence of adverse events that cannot be ruled out as being caused by the vaccine were calculated to assess the safety of CoronaVac®. This study is registered with ClinicalTrials. Gov (NCT04911790 and NCT04992208).

RESULTS

A total of 162,691 participants have been included in this study and 89.50 % had finished primary immunization. Among adults and elderly, people with UMCs accounted for 25.85 %, with the top five disease being hypertension, diabetes, chronic gastritis, coronary heart disease(CHD) and kidney stone. The overall incidence of adverse reactions (ARs) within 6 months after the second vaccination was 2.70 %, with incidence for children and adolescents, adults, and elderly being 2.03 %, 3.46 %, and 1.90 %, respectively. Most ARs were mild (grade 1). Pain at the injection sites, fatigue, induration/swelling, and headache were the most common symptoms, occurring in 1.64 %, 0.46 %, 0.31 % and 0.24 %, respectively. No serious adverse events related to vaccines were reported. No adverse events of special interest (AESIs) were identified. For children and adolescents, children aged 3-5 years had the highest incidence of ARs of 3.29 %. The incidence of ARs among those aged 18 years and older with and without UMCs were 2.81 % and 2.99 %, respectively, with no statistical significance between two groups(P = 0.089). And people with coronary heart disease had higher AR incidence compared to those with other UMCs, but the most common symptoms was pain at the injection site.

CONCLUSION

CoronaVac® is safe in a large-scale use and shows well-tolerance for children and adolescents and people with underlying medical conditions. Further studies need to be conducted to explore the relation of ARs incidence to age or different kinds of UMCs.

Comparison of COVID-19 Vaccine-Associated Myocarditis and Viral Myocarditis Pathology

The COVID-19 pandemic has led to significant loss of life and severe disability, justifying the expedited testing and approval of messenger RNA (mRNA) vaccines. While found to be safe and effective, there have been increasing reports of myocarditis after COVID-19 mRNA vaccine administration. The acute events have been severe enough to require admission to the intensive care unit in some, but most patients fully recover with only rare deaths reported. The pathways involved in the development of vaccine-associated myocarditis are highly dependent on the specific vaccine. COVID-19 vaccine-associated myocarditis is believed to be primarily caused by uncontrolled cytokine-mediated inflammation with possible genetic components in the interleukin-6 signaling pathway. There is also a potential autoimmune component via molecular mimicry. Many of these pathways are similar to those seen in viral myocarditis, indicating a common pathophysiology. There is concern for residual cardiac fibrosis and increased risk for the development of cardiomyopathies later in life. This is of particular interest for patients with congenital heart defects who are already at increased risk for fibrotic cardiomyopathies. Though the risk for vaccine-associated myocarditis is important to consider, the risk of viral myocarditis and other injury is far greater with COVID-19 infection. Considering these relative risks, it is still recommended that the general public receive vaccination against COVID-19, and it is particularly important for congenital heart defect patients to receive vaccination for COVID-19.

From Immunogen to COVID-19 vaccines: Prospects for the post-pandemic era

The COVID-19 pandemic has affected millions of people and posed an unprecedented burden on healthcare systems and economies worldwide since the outbreak of the COVID-19. A considerable number of nations have investigated COVID-19 and proposed a series of prevention and treatment strategies thus far. The pandemic prevention strategies implemented in China have suggested that the spread of COVID-19 can be effectively reduced by restricting large-scale gathering, developing community-scale nucleic acid testing, and conducting epidemiological investigations, whereas sporadic cases have always been identified in numerous places. Currently, there is still no decisive therapy for COVID-19 or related complications. The development of COVID-19 vaccines has raised the hope for mitigating this pandemic based on the intercross immunity induced by COVID-19. Thus far, several types of COVID-19 vaccines have been developed and released to into financial markets. From the perspective of vaccine use in globe, COVID-19 vaccines are beneficial to mitigate the pandemic, whereas the relative adverse events have been reported progressively. This is a review about the development, challenges and prospects of COVID-19 vaccines, and it can provide more insights into all aspects of the vaccines.

A Retrospective Evaluation of Self-Reported Adverse Events Following Immunization with Different COVID-19 Vaccines in Türkiye

BACKGROUND

The Sinovac and BioNTech vaccines were the first to be introduced in Türkiye to fight the ongoing global COVID-19 pandemic. As these vaccines had shown some side-effects in its clinical trial, we aimed to conduct a survey study to assess the short-term adverse events following immunization (AEFIs) in Türkiye.

METHOD

A cross-sectional study was conducted using social and electronic media platforms by delivering a pre-formed and validated online questionnaire among people who had received at least one dose of the COVID-19 vaccine. This survey study focused on mass populations from different regions in Türkiye. A total of 603 responses were collected. Among these, 602 were selected based on complete answers and used for the assessment. The collected data were then analyzed to evaluate the various parameters related to the AEFIs of the respondents.

RESULTS

Among the total 602 participants, 20.8% were male, and 78.7% were female, actively answering all of the constructive questions. Most of the respondents were between 18-30 years of age. We found that a total of 23.3% of the total respondents had been infected with the SARS-CoV-2 virus. Our survey revealed that out of 602 volunteers, the rate of experiencing physical discomfort was higher in participants who had received the Pfizer-BioNTech vaccine at all three doses than in those who had received the Sinovac vaccine. When all vaccine types were examined, the most common side effect was pain at the injection site, reported by 75.19% participants. When the side effects were compared according to vaccine types, there was a significant difference only in terms of fever. Fever rates in those who had received the Pfizer-BioNTech vaccine (20.96%) were found to be significantly higher than those who had received the Sinovac vaccine (8%).

CONCLUSIONS

The studied vaccines showed minor side effects and there was no significant difference between the vaccines in terms of other side effects. Moreover, further research is needed to determine the efficacy of the existing vaccines in preventing SARS-CoV-2 infections or after-infection hospitalization.