Adverse event reports of anaphylaxis after Comirnaty and Vaxzevria COVID-19 vaccinations, Western Australia, 22 February to 30 June 2021.

Within the first 4 months of the Western Australian COVID-19 immunisation programme, 49 suspected anaphylaxis cases were reported to the vaccine safety surveillance system. Twelve reports met Brighton Collaboration case definition, corresponding to rates of 15.9 and 17.7 per million doses of Vaxzevria and Comirnaty administered respectively.

Understanding and experience of adverse event following immunization (AEFI) and its consequences among healthcare providers in Kebbi State, Nigeria: a qualitative study.

BACKGROUND: Vaccines used in the national immunization program are relatively safe and effective. However, no vaccine is perfectly safe. Therefore, adverse reactions may occur. This study aimed to investigate the understanding and experience of Adverse Event Following Immunization (AEFI) among healthcare workers and Routine Immunization (RI) officers. METHODS: Phenomenological qualitative study was conducted between June and September 2019, using a semi-structured question guide in Kebbi State, Northwest Nigeria. Face-to-face interviews were conducted with 12 RI providers, eight Expanded Program on Immunization (EPI) officers, and eight Disease Surveillance and Notification Officers. Thematic analysis was used to analyze the data. The interviews were transcribed and translated, then manually analyzed thematically. RESULTS: The knowledge level of healthcare providers on AEFI definition and classification varied and was suboptimal. Error during vaccination was the study participants' most frequently mentioned possible cause of AEFI. Persistent crying, fever, fainting, and swelling and tenderness at injection sites were the AEFI experienced by the healthcare providers in their careers. Block rejection, lower immunization uptake, loss of confidence in RI, attack on RI providers, discrimination of RI providers and divorce threats among spouses were the consequences of AEFI. Supportive supervision of the RI sessions, refresher training on safe injection for RI providers, and symptomatic treatment of clients with AEFI would prevent AEFI consequences. Also, educating caregivers, community sensitization, and dialogue would minimize the consequences of AEFI. CONCLUSIONS: Evidence of a sub-optimal understanding of AEFI was established in this study. Hence, policymakers should consider regular refresher training on AEFI to ensure all RI providers have an optimal understanding of AEFI. Health education of caregivers and parents during RI sessions and community engagement should be considered to minimise AEFI consequences on the immunization program and the society.

Vaccine adverse event reporting system (VAERS): Evaluation of 31 years of reports and pandemics' impact.

Background: Vaccine adverse event reporting system (VAERS) was established in the United States (U.S.) as an early warning system with a main purpose of collecting post-marketing Adverse events following immunizations (AEFIs) reports to monitor the vaccine safety and to mitigate the risks from vaccines. During the coronavirus diseases 2019 (COVID-19) pandemic, VAERS got more attention as its important role in monitoring the safety of the vaccines. The aim of this study was to investigate VAERS patterns, reported AEFI, vaccines, and impact of different pandemics since its inception. Methods: This was an observational study using VARES data from 2/7/1990 to 12/11/2021. Patterns of reports over years were first described, followed by a comparison of reports statistics per year. Furthermore, a comparison of incidents (death, ER visits, etc.) statistics over years, in addition to statistics of each vaccine were calculated. Moreover, each incident's statistics for each vaccine were calculated and top vaccines were reported. All analyses were conducted using R (Version 1.4.1717) and Excel for Microsoft 365. Results: There were 1,396,280 domestic and 346,210 non-domestic reports during 1990-2021, including 228 vaccines. For both domestic and non-domestic reports, year of 2021 had the highest reporting rate (48.52 % and 70.33 %), in addition a notable change in AEFIs patterns were recorded during 1991, 1998, 2000, 2006, 2009, 2011, and 2017. AEFIs were as follow: deaths (1.00 % and 4.08 %), ER or doctor visits (13.37 % and 2.27 %), hospitalizations (5.84 % and 27.78 %), lethal threat (1.42 % and 4.38 %), and disabilities (1.4 % and 7.96 %). Pyrexia was the top reported symptom during the past 31 years, except for 2021 where headache was the top one. COVID-19 vaccines namely Moderna, Pfizer-Biontech, and Janssen were the top 3 reported vaccines with headache, pyrexia, and fatigue as the top associated AEFIs. Followed by Zoster, Seasonal Influenza, Pneumococcal, and Human papillomavirus vaccines. Conclusions: The large data available in VARES make it a useful tool for detecting and monitoring vaccine AEFIs. However, its usability relies on understating the limitations of this surveillance system, the impact of governmental regulations, availability of vaccines, and public health recommendations on the reporting rate.

Vaccine hesitancy: evidence from an adverse events following immunization database, and the role of cognitive biases.

BACKGROUND: Vaccine hesitancy has been a growing challenge for public health in recent decades. Among factors contributing to vaccine hesitancy, concerns regarding vaccine safety and Adverse Events (AEs) play the leading role. Moreover, cognitive biases are critical in connecting such concerns to vaccine hesitancy behaviors, but their role has not been comprehensively studied. In this study, our first objective is to address concerns regarding vaccine AEs to increase vaccine acceptance. Our second objective is to identify the potential cognitive biases connecting vaccine hesitancy concerns to vaccine-hesitant behaviors and identify the mechanism they get triggered in the vaccine decision-making process. METHODS: First, to mitigate concerns regarding AEs, we quantitatively analyzed the U.S. Vaccine Adverse Event Reporting System (VAERS) from 2011 to 2018 and provided evidence regarding the non-severity of the AEs that can be used as a communicable summary to increase vaccine acceptance. Second, we focused on the vaccination decision-making process. We reviewed cognitive biases and vaccine hesitancy literature to identify the most potential cognitive biases that affect vaccine hesitancy and categorized them adopting the Precaution Adoption Process Model (PAPM). RESULTS: Our results show that the top frequent AEs are expected mild reactions like injection site erythema (4.29%), pyrexia (3.66%), and injection site swelling (3.21%). 94.5% of the reports are not serious and the average population-based serious reporting rate over the 8 years was 25.3 reports per 1 million population. We also identified 15 potential cognitive biases that might affect people's vaccination decision-making and nudge them toward vaccine hesitancy. We categorized these biases based on the factors that trigger them and discussed how they contribute to vaccine hesitancy. CONCLUSIONS: This paper provided an evidence-based communicable summary of VAERS. As the most trusted sources of vaccine information, health practitioners can use this summary to provide evidence-based vaccine information to vaccine decision-makers (patients/parents) and mitigate concerns over vaccine safety and AEs. In addition, we identified 15 potential cognitive biases that might affect the vaccination decision-making process and nudge people toward vaccine hesitancy. Any plan, intervention, and message to increase vaccination uptake should be modified to decrease the effect of these potential cognitive biases.

Adverse Events Following Immunization Associated with Coronavirus Disease 2019 Vaccination Reported in the Mobile Vaccine Adverse Events Reporting System.

BACKGROUND: Vaccination against coronavirus disease 2019 (COVID-19) is underway globally to prevent the infection caused by the severe acute respiratory syndrome coronavirus 2. We aimed to investigate the adverse events following immunization (AEFIs) for COVID-19 among healthcare workers (HCWs). METHODS: This was a retrospective study of the AEFIs associated with the first dose of the ChAdOx1 nCoV-19 vaccine at the Kosin University Gospel Hospital from March 3 to March 22, 2021. We investigated the systemic and local adverse events during the 7 days following the vaccination using the Mobile Vaccine Adverse Events Reporting System (MVAERS) developed by our hospital. RESULTS: A total of 1,503 HCWs were vaccinated, and the data of 994 HCWs were reported in the MVAERS. The most commonly reported AEFIs were tenderness at the injection site (94.5%), fatigue (92.9%), pain at the injection site (88.0%), and malaise (83.8%). The severity of most AEFIs was mild-to-moderate, and the severity and number of AEFIs were less in the older age group. There were no serious events requiring hospitalization, and most AEFIs improved within a few days. CONCLUSION: The AEFIs associated with the ChAdOx1 nCoV-19 vaccine were tolerable, and the use of the MVAERS was helpful in monitoring the AEFIs. The use of MVAERS will help in sharing accurate and ample information about vaccination against COVID-19.

Temporal association between serious bleeding and immunization: vitamin K deficiency as main causative factor.

BACKGROUND: Bleeding as an adverse event following immunization (AEFI) that is rarely reported in children, although it can be a parental concern. Bleeding episodes ranging in severity from mild to severe and defined as any external and/or internal bleeding can be caused by acquired or hereditary disorders. This study analyzes whether bleeding episodes in children that were recorded as AEFIs are causally associated with immunization and elaborates their etiology. METHODS: A cross-sectional study of 388 AEFI cases in children from West Java Provincial Committee in Indonesia confirmed by case findings from 2000 until 2017. RESULTS: Of the total number of cases studied, 55 (14%) involved children aged 5 days to 12 years who presented with bleeding and were referred to a provincial hospital. Analysis revealed that 32 cases were most likely caused by acquired prothrombin complex deficiency (APCD) and 30 of these APCD cases were strongly suspected to be manifestations of vitamin K deficiency bleeding (VKDB). All VKDB subjects were aged 5 days to 3 months without a history of administration of prophylactic vitamin K. When a World Health Organization classification was used, most bleeding cases in this study became coincidental events with a temporal association with immunization. A causality assessment suggested that these cases were causally unrelated. CONCLUSION: Most cases of bleeding reported as an AEFI were found to be VKDB, which is considered a coincidental event following immunization with a temporal association, and an unrelated category based on the results of a causality assessment. Vitamin K should be administered to all newborns as a prophylactic and AEFI surveillance should be improved based on the low numbers of AEFI reported in Indonesia.

2017/18 and 2018/19 seasonal influenza vaccine safety surveillance, Canadian National Vaccine Safety (CANVAS) Network.

BackgroundThe Canadian National Vaccine Safety (CANVAS) network monitors the safety of seasonal influenza vaccines in Canada.AimTo provide enhanced surveillance for seasonal influenza and pandemic influenza vaccines.MethodsIn 2017/18 and 2018/19 influenza seasons, adults (≥ 15 years of age) and parents of children vaccinated with the seasonal influenza vaccine participated in an observational study using web-based active surveillance. Participants completed an online survey for health events occurring in the first 7 days after vaccination. Participants who received the influenza vaccine in the previous season, but had not yet been vaccinated for the current season, were unvaccinated controls.ResultsIn 2017/18, 43,751 participants and in 2018/19, 47,798 completed the online safety survey. In total, 957 of 30,173 participants vaccinated in 2017/18 (3.2%; 95% confidence interval (CI): 3.0-3.4) and 857 of 25,799 participants vaccinated in 2018/19 (3.3%; 95% CI: 3.1-3.5) reported a health problem of sufficient intensity to prevent their normal daily activities and/or cause them to seek medical care (including hospitalisation). This compared to 323 of 13,578 (2.4%; 95% CI: 2.1-2.6) and 544 of 21,999 (2.5%; 95% CI: 2.3-2.7) controls in each respective season. The event rate in vaccinated adults and children was higher than the background rate and was associated with specific influenza vaccines. The higher rate of events was associated with systemic symptoms and migraines/headaches.ConclusionIn 2017/18 and 2018/19, higher rates of events were reported following seasonal influenza vaccination than in the pre-vaccination period. This signal was associated with several seasonal influenza vaccine products.

Adverse events following immunisation (AEFI) reports from the Zimbabwe expanded programme on immunisation (ZEPI): an analysis of spontaneous reports in Vigibase® from 1997 to 2017.

BACKGROUND: Vaccine safety surveillance is an essential requirement in vaccination programmes. It supports signal identification, hypothesis generation, and the identification and rectification of gaps in vaccine pharmacovigilance systems. The objectives of this study were to determine the characteristics and trends of adverse events following immunisation (AEFI) and to assess the performance of the Zimbabwe Expanded Immunisation Programme safety surveillance system. METHODS: We carried out a descriptive study of passively collected vaccine-related Individual Case Safety Report (ICSR) data submitted to the World Health Organization global adverse drug reaction database (VigiBase®) from Zimbabwe during the period 1997 to 2017. We extracted AEFI/ICSR data using VigiLyze® for analysis with respect to the demographic distribution, AEFI characteristics, reporting trends over time, ICSR timeliness and case completeness. RESULTS: A total of 272 vaccine-related ICSRs were included in the analyses with a median completeness score of 0.90 interquartile range, IQR (0.63; 0.90). The overall annual reporting rate was 0.58 per 100,000 vaccine doses and the AEFI reporting ratio ranged between 0 and 30.2 AEFI reports per 100,000 surviving infants. The majority of ICSRs were male (55.3%; p value = 0.641) and the median age was 12 (0-168) months. The majority of ICSRs were reported in children who had received measles (n = 133; 48.9%) and OPV/DTP-Hib-HepB (n = 107; 39.3%) vaccines. Of the 387 observed AEFIs, 301 (77.8%) were systemic events and 86 (22.2%) were local reactions. Systemic events were more frequently reported with doses containing the measles antigen (n = 190; 49.1%) while local events were associated with the multiple antigen OPV/DTP-Hib-HepB (n = 62; 16.0%). The multiple antigen OPV/DTP-Hib-HepB was associated with higher rates for injection site abscess (n = 57), pyrexia (n = 27), diarrhea (n = 15), vomiting (n = 12), and seizures (n = 6). The measles antigen was associated with higher rates for rash (n = 44), ocular disorders (n = 26), pyrexia (n = 26), urticaria (n = 22), diarrhea (n = 8), and vomiting (n = 12). CONCLUSIONS: Most of the ICSRs were associated with measles and OPV/DTP-Hib-HepB vaccines. Zimbabwe's vaccine safety surveillance system is still developing and is not yet fully functional. However, the current system provides a reference point for the monitoring of the ongoing AEFI reporting trends and characteristics.

Surveillance of adverse events following immunization in Oman, 2006-2015.

BACKGROUND: In 1996, Oman launched its surveillance programme for adverse events following immunization (AEFI) to address vaccine safety concerns. In 2010, an analysis of surveillance activities for AEFI was done for 10 years (1996-2005). OBJECTIVES: The main objective of the study was to describe the trend of AEFI over the 10-year period, 2006-2015, and compare the findings with a previous report in Oman and reports from other countries. METHODS: A descriptive record-based review of AEFI was carried out using the national AEFI surveillance database for the study period, 2006-2015. RESULTS: A total of 890 adverse event reports were received, giving an annual rate during the review period of 21.4 per 100 000 population or 8.3 per 100 000 doses administered. The most frequently reported AEFI were BCG adenitis and local reactions - 31.1 and 4.1 per 100 000 doses respectively. There were no reported deaths. Pentavalent vaccine was responsible for the greatest proportion of adverse events (30%). Local reaction was the most common adverse event among all vaccines administered. The Hexa vaccine caused fewer adverse events compared with the pentavalent vaccine, probably due to the acellular pertussis component - 0.8 versus 1.5 per 100 000 doses administered respectively. CONCLUSION: The overall rate of AEFI (8.3 per 100 000 doses administered) is comparable to the rate (10.8/100 000 doses) in the previous decade (1996-2005) in Oman. The reported rates for individual vaccines are similar to or below international rates.

Canada's eight-component vaccine safety system: A primer for health care workers.

Concerns about vaccine safety make some parents hesitant about immunization. Health care providers are pivotal in helping parents understand that Canada is a leader in vaccine safety. The present practice point provides an update on the eight components of Canada's vaccine safety system: (1) an evidence-based pre-license review and approval process; (2) strong regulations for manufacturers; (3) independent evidence-based vaccine use recommendations; (4) immunization competency training and standards for health care providers; (5) pharmacovigilance programs to detect and (6) determine causality of adverse events following immunization (AEFIs); (7) a program for vaccine safety and efficacy signal detection; and (8) the Canadian Immunization Research Network's special immunization clinics for children who have experienced serious AEFIs.

Canada's eight-component vaccine safety system: A primer for health care workers.

Concerns about vaccine safety make some parents hesitant about immunization. Health care providers are pivotal in helping parents understand that Canada is a leader in vaccine safety. The present practice point provides an update on the eight components of Canada's vaccine safety system: (1) an evidence-based pre-license review and approval process; (2) strong regulations for manufacturers; (3) independent evidence-based vaccine use recommendations; (4) immunization competency training and standards for health care providers; (5) pharmacovigilance programs to detect and (6) determine causality of adverse events following immunization (AEFIs); (7) a program for vaccine safety and efficacy signal detection; and (8) the Canadian Immunization Research Network's special immunization clinics for children who have experienced serious AEFIs.

Incidence and types of adverse events during mass vaccination campaign with the meningococcal a conjugate vaccine (MENAFRIVAC™) in Cameroon.

PURPOSE: A new vaccine against meningitis A was introduced in Africa meningitis belt in 2010. This study was planned to describe the incidence and types of adverse events following immunization (AEFIs) with a new conjugate vaccine against meningitis A (MenAfrivac™) in a Cameroonian vaccination campaign. METHODS: The campaign was conducted in Adamawa and North West regions in December 2012 and the AEFIs enhanced surveillance from December 2012 to January 2013. Incidence rates (IR) of overall and serious AEFIs were estimated as well as AEFI incidence rates by type, age group and region. AEFI symptoms were aggregated in System Organ Class (SOC). RESULTS: Of 2 093 381 persons vaccinated, 1352 AEFIs were reported. Of these, 228 (16.9%) were excluded because of not meeting inclusion criteria and 1124 (83.1%) included (IR: 53.7/100 000 doses administered/8 weeks). Of the 82 serious AEFIs reported, 52 (63.2%) met the case definition. 23 (28.1%) were investigated, of which 4 (17.4%) were probably vaccine product-related reactions (IR: 0.2/100 000 doses administered/8 weeks). Fever was the most common reported AEFI with 626 cases (IR: 31.4/100 000 doses administered/8 weeks). The proportion of people with the SOC "Gastrointestinal disorders" was significantly lower in ages 5-15 and 16-29 years than 1-4 years [aRR = 0.63(0.42-0.93) and 0.54(0.36-0.81) respectively]. CONCLUSION: Incidence and types of AEFI reported during MenAfriVacTM vaccination campaign organized in Cameroon in 2012 did not suggest concern regarding the vaccine safety. Differences in frequency of AEFIs types per age group could guide the monitoring of AEFIs frequency in future campaigns. Efforts are needed to improve the investigation rate of serious AEFIs. Copyright © 2016 John Wiley & Sons, Ltd.

Surveillance for adverse events following immunization (AEFI) for 7 years using a computerised vaccination system.

OBJECTIVES: The surveillance of vaccine safety is an essential requirement in vaccination programmes. Computerized immunization registries such as the Vaccination Information System (SIV) of Valencian Community (Spain) offer the opportunity to estimate the incidence of adverse events according to individual information. The aim of the study was to analyze adverse events following immunization reported through SIV from 2005 to 2011 by age, sex, type of vaccine and dose, and adverse event, and highlight the advantages of this type of reporting. STUDY DESIGN: A retrospective cohort study of subjects vaccinated in the Valencian Community using population health databases was carried out. METHODS: Analysis of vaccinations and reported AEFI via SIV in Valencian Community was carried out. RESULTS: More than 13 million vaccines doses were administered during 2005 through 2011, the reporting rate of adverse events was 12.4/100,000 doses administered with the highest value in 2009 (27.4), with differences by age and sex. DTaP vaccine had the highest reporting in children (96.6/100,000) while influenza A(H1N1)pdm09 in adults (87.7/100,000). An increased reporting of adverse events was seen with DTaP in children 5-6 years of age, detected in real time, drove to swap this vaccine to a low dose Tdap which was followed by a decrease in administration site events. CONCLUSIONS: SIV demonstrates advantages for passive surveillance. Reporting rates by individual characteristics are calculated accurately and it also allows detecting shifts in reporting rate on real time for specific vaccines. The study shows that vaccines included in the routine vaccination schedule for children and adult vaccination programs are safe.

Lessons Learned From Enhancing Vaccine Pharmacovigilance Activities During PsA-TT Introduction in African Countries, 2010-2013.

BACKGROUND: The rollout of the group A meningococcal vaccine, PsA-TT, in Africa's meningitis belt countries represented the first introduction of a vaccine specifically designed for this part of the world. During the first year alone, the number of people who received the vaccine through mass vaccination campaigns was several hundredfold higher than that of subjects who participated in the closely monitored clinical trials. Implementation of a system to identify rare but potentially serious vaccine reactions was therefore a high priority in the design and implementation of those campaigns. METHODS: National authorities and their technical partners set up effective vaccine pharmacovigilance systems, including conducting active surveillance projects. RESULTS: Implementation of national expert advisory groups to review serious adverse events following immunization in all countries and active monitoring of conditions of interest in 3 early-adopter countries did not identify particular concerns with the safety profile of PsA-TT, which had already provided tremendous public health benefits. CONCLUSIONS: Lessons learned from this experience will help to improve preparations for future vaccine introductions in resource-poor settings and capitalize on such efforts to advance vaccine safety systems in the future.

Ongoing pharmacovigilance on vaccines.

Vaccines have peculiar characteristics as well as their surveillance. Specific requirements, needs and challenges for the vaccine vigilance are discussed in the perspective to improve the whole system in order to guarantee a safer vaccine use and the keeping of the public confidence in vaccinations. Key elements for the routine safety monitoring, new regulations and some available tools are taken into account. Finally, the Italian experience is shortly described.

Side effects of CoronaVac® COVID-19 vaccination: Investigation in North Jakarta district public health center communities in Indonesia.

Background: The decreasing prevalence of COVID-19 has highlighted the value of vaccinations. CoronaVac® vaccine was one of the most widely used vaccines in Indonesia, in other Southeast Asian countries, as well as in Latin America. However, to date the safety and side effect profiles of CoronaVac® vaccine among the Indonesian population have not been reported. Objective: In this study, the CoronaVac® safety profiles were determined in a community of a public health center in North Jakarta, Indonesia. Method: This is a descriptive cross-sectional questionnaire-based study on vaccine side effects as recorded in the yellow form (MESO). Patients (n = 300) who received CoronaVac® vaccinations between July and August 2021 were enrolled. SPSS was used to analyze the descriptive data. Results: Most respondents were women (72.7 %) between the ages of 17 and 21 years. A significantly (p = 0.009) positive correlation was established between the vaccine side effects (namely pain at the injection site) with the female gender. Other side effects such as fatigue (p = 0.034) and headache (p < 0.001) were also correlated with disease comorbidity. Conclusion: Overall, the side effects following the first and the second doses were generally mild and included fever, pain in the injection area, fatigue, headache, drowsiness, diarrhea, cough, and nausea. Regarding vaccine efficacy, CoronaVac® confers better protection following the second dose administration where the percentage of respondents affected with COVID-19 (26.7 %) decreased to only 20.3 % following the second dose.

Surveillance of adverse events following immunisation in Australia annual report, 2021.

Abstract: This report summarises Australia's spontaneous surveillance data for adverse events following immunisation (AEFI) for 2021 reported to the Therapeutic Goods Administration (TGA) and describes reporting trends over the 22-year period 1 January 2000 to 31 December 2021. This report excludes AEFI reports featuring pandemic coronavirus disease 2019 (COVID-19) vaccines, which are reported separately. There were 3,452 AEFI reports for non-COVID-19 vaccines administered in 2021, an annual AEFI reporting rate of 13.4 per 100,000 population compared with 14.9 per 100,000 population in 2020. This small decrease in the AEFI reporting rate in 2021 could potentially be related to an increased focus on COVID-19 vaccines and related AEFI, which are not included in this report. AEFI reporting rates for individual vaccines in 2021 were similar to 2020, as were the most commonly reported adverse events. Of the six deaths following vaccination in 2021 reported to the TGA, none were found to have a causal relationship with vaccination.

Safety Surveillance of Covishield Vaccine-Associated Adverse Events During the COVID-19 Pandemic: A Retrospective Longitudinal Study.

BACKGROUND: Adverse events following immunization (AEFI) must be reported and assessed to promote patient safety. This longitudinal study examined the nature and severity of adverse events reported after Covishield (Serum Institute of India, Pune, India) vaccine administration to North Indians in a tertiary care hospital. METHOD: A retrospective evaluation of adverse drug reactions (ADRs) reported after Covishield vaccine administration in our hospital over 18 months was conducted. The assessment was carried out to analyze the pattern of ADRs reported by individuals receiving the Covishield vaccine from January 2021 to June 2022. Data such as age, gender, category, dose administered, type of ADR, duration of the event, medical history, and outcome of the reactions were collected. Each reported adverse event was assessed individually. Causality was determined using the WHO-UMC causality assessment scale. The data were analyzed and are expressed as mean ± standard deviation and percentage. RESULTS: A total of 14,590 individuals were vaccinated at our study center from January 2021 to June 2022. During this period, 146 AEFIs (1.0%) were reported at our ADR monitoring center, Employees' State Insurance Corporation Medical College and Hospital (ESIC MCH), Faridabad, India. The majority of AEFIs were systemic, were reported after the first dose, and had an onset within 12 hours after vaccination. Fever, injection site pain, drowsiness, headache, vomiting, swelling, tenderness, and body aches were the most commonly reported adverse effects. No significant relationships were observed between the administered vaccine dose and sex, severity, duration of the event, or outcome. However, the incidence of adverse events was greater with the first vaccine dose than with the second dose. The possibility of serious or fatal adverse events was lowest in the general population and higher in the elderly with comorbidities. CONCLUSION: The data suggest that the Covishield vaccine had mild to moderate adverse effects on the study population. This pharmacovigilance study will complement safety data and aid in the benefit-risk analysis of adverse effects associated with the Covishield vaccine. Additionally, healthcare professionals should be encouraged to conduct further safety studies by establishing robust vaccine safety monitoring systems in hospitals. Continuing medical education and workshops should also be conducted to educate healthcare workers about active surveillance.

Assessment of safety and adverse events following COVID-19 vaccination and their predictors in first 30 days among healthcare workers of a tertiary care teaching hospital in North India.

Background: The COVID-19 vaccines were rolled out as an emergency measure, with an expedited approval to contain the pandemic. The objective of this study was to assess the incidence, pattern and severity of AEFIs reported following COVID-19 vaccination and their predictors among the healthcare workers. Materials and methods: A prospective cohort study enrolling healthcare workers of a tertiary care Institute in North India receiving COVISHIELD™ from February to May 2021 was carried out to assess the incidence, pattern and severity of AEFI over the next 30 days. Both active and passive surveillance methods were used for AEFI recording. Bivariate analysis was performed to ascertain the predictors of AEFIs. Results: A total of 836 healthcare workers who received the first dose of COVISHIELD™ were included in the study of which 201 (24.0 %) experienced one or more AEFIs. Majority of AEFIs were of minor grade (99.8 %) and resolved spontaneously. Majority (96.0 %) had onset of the AEFIs within 48 hrs of vaccination. Serious AEFIs, leading to hospitalization was noticed in 2(0.2 %) participants, both females, with suspicion of immunization stress related response (ISRR). Both of them recovered without any sequelae. No deaths were recorded. Factors found to be significantly associated with the occurrence of AEFIs in the participants were female gender (p = 0.02), monthly income > 20,000 INR (p = 0.007), presence of any chronic illness (p < 0.0001), history of allergic reaction to any drug/vaccine (p = 0.01), history of COVID-19 infection (p < 0.00002) and history of hospitalization due to COVID-19 (p < 0.0002). Conclusion: Majority of the AEFIs observed were of minor grade with spontaneous resolution of the symptoms indicating safety and well tolerability of the vaccine. Female gender, higher income, history of allergy and co-morbidities, history of COVID-19 infection and history of hospitalization were found to be major predictors for the development of adverse events and require more watchful vaccination.