Adverse effects after first and second dose of covishield and covaxin: A longitudinal study

COVID-19 vaccines have been rolled out recently in several parts of the world. Although the protective efficacy is frequently discussed, little is known about the factors associated with COVID-19 vaccine adverse effects. The study was conducted with the aim to evaluate the occurrence of adverse events following immunization (AEFI) with two doses of covishield and covaxin and to assess factors associated with these adverse effects.

A longitudinal study was conducted for a period of three months in the adults above 18 years of age attending rural health training center (RHTC) either to receive their first or second dose of covishield or covaxin. After vaccination, the participants were observed at the health facility for 30 min for any AEFI and also followed up telephonically on seventh day from vaccination. Data was collected on predesigned and pretested questionnaire and appropriate statistical tests were applied.

Out of 532 participants, 250 (47%) came for their first dose while 282 (53%) came for second dose. In both the groups maximum participation was seen by males and those belonging to age group 18-30 years. Majority of the participants reported local tenderness (39.3%) after first dose of covaxin and fever (30.5%) after first dose of covishield. Mainly significant association was observed after vaccination in participants with comorbidities.

The short-term adverse events with both the vaccines were observed, but these were mild and short lived. In this context, our study becomes more relevant in disseminating short-term safety data post vaccination. This will help individuals in their decision to accept vaccination.