(281) Adverse Events Following COVID-19 Immunization: Active Vaccine Safety Study from a South Indian City

Publication Number: 1326

Background: The COVID-19 vaccination program was introduced in India in January 2021. Less information regarding the Adverse Events Following Immunizations (AEFIs) was also one of the reasons for vaccine hesitancy among the population for COVID-19 vaccines.

Objectives: Objective of the study was to assess the Adverse Events following COVID-19 vaccination.

Methods: Active vaccine safety surveillance was held among the beneficiaries of COVID-19 vaccination in a vaccination center for one-year duration. Study population was enrolled from the vaccination centre of a tertiary care hospital after the informed consent during their first dose vaccination visit. All the enrolled participants were followed telephonically after each dose of vaccines (visit 1: 8 ± 2 and Visit 2: 28 ±2 days). Collected data were analyzed and categorized by severity and seriousness. The causality assessment team performed causality assessment of the AEFIs using the World Health Organization’s causality assessment algorithm. Bivariate analysis was used as the statistical tool (confidence interval of 95%) for the identification of predictors of AEFI.

Results: A total of 43037 doses of COVID-19 vaccine (COVISHIELDTM – 14131 , COVAXINTM- 28906) were administered at the study site during the study period. A total of 694 AEFIs were reported from 496 subjects with an incidence rate of 0.99%. Incidence of AEFIs were less with COVAXINTM (0.25%). 86.02% of reported events were expected as per the fact sheets issued by the manufacturers. 62.02% AEFIs were observed at the system organ class of ‘General disorders and administration site conditions’. After the causality assessment, 94.22% events were categorized to have ‘consistent causal association with immunization’. 98.02% of the study population recovered from their adverse events without any sequelae. Adult age group (18-45 years), co-morbidities and first dose was the identified predictors for AEFIs.

Conclusions: Active vaccine safety surveillance helps health care professionals to identify rare events and potential signals. The incidence rate was less and events were mild in severity. Number of anxiety related events were high in the first quarter of the study and the same was nil in the last quarter of the study. These kinds of systematic studies and data analysis help the HCPs to bring down the vaccine hesitancy.