Analysis of participant-reported adverse events following the first dose of inactivated SARS-Cov-2 vaccine (TURKOVAC™) through telephone survey in Türkiye.

Background/objective(s)/introduction: TURKOVAC™ is a whole-virion inactivated COVID-19 vaccine, which was developed and recently granted emergency use authorization (conditional marketing authorization) in Türkiye. The objective of this study is to assess the spectrum and the distribution of adverse events reported following the administration of the first 150,000 doses as primary and booster vaccine doses in 22 state hospitals of 17 provinces in Türkiye.

Patients/materials And Methods: In this cohort study, a verbal survey was conducted telephone calls between 10 January and 17 January 2022, utilizing a structured questionnaire algorithm on a sample group of 20,000 persons on the third- and seventh-days following vaccination. The algorithm consisted of two parts focusing on both systemic and local adverse effects. Other adverse events reported by the participants were also recorded. 6023 people and 5345 people agreed to participate in the telephone survey on the 3rd- and 7th- days of having received the first dose of the vaccine, respectively.

Results: Thirty-six-point-six percent of the participants on the 3rd day and 22.5% of the participants on the 7th day reported any adverse event following the first dose of the vaccine. On both follow-up days, the most commonly reported (29.7% for Day 3 and 13.1% for Day 7) adverse events were on the injection site. Among the local adverse events, the most frequently reported one was the pain on the injection site (27.9% for Day 3 and 12.4% for Day 7), induration (4.8% for Day 3 and 2.7% for Day 7) and swelling (3.5% for Day 3 and 2.0% for Day 7). Fatigue/weakness (9.6% for Day 3 and 8.3% for Day 7) and headache (7.9% for Day 3 and 8.0% for Day 7) were the most frequent systemic adverse events. Younger age, vaccine dose, and female sex were associated with having any adverse event and pain (on the injection site). Female sex was associated with more swelling (on the injection site), induration (on the injection site), fever, and a higher impact on daily living.

Conclusion(s): In this study, we conducted a rapid assessment of adverse events following the first dose of the TURKOVAC vaccine. The vaccine appears to have a good safety profile in the first 7 days following vaccination. Younger age, vaccine dose, and female sex are associated with any adverse event and pain (on the injection site). These results present valuable information for the community and may contribute to increasing vaccine confidence.KEY MESSAGESAs a whole-virion inactivated SARS-CoV-2 vaccine, the TURKOVAC™ vaccine, which has a favorable safety profile, can be an alternative to other COVID-19 vaccines including mRNA and viral vector vaccines.