Anaphylaxis is rare due to CoronaVac in a population of healthcare workers

Abstract

CoronaVac, the first coronavirus disease 2019 vaccine administered in our country, was found safe in clinical trials. We aimed to reveal the rate and features of CoronaVac vaccine-associated allergic reactions among vaccinated healthcare workers (HCWs) in real-life. This study was planned as a questionnaire-based study. Participants who reported a postvaccination allergic reaction were interviewed on phone and their medical records were also checked for confirmation. A total of 2,488 HCWs took part in the study and 4,054 postvaccination complete questionnaire-responses were obtained. Twenty-one HCWs (female: male, 17:4) with a mean age of 40.95 ± 10.09 stated that they had an allergic reaction after a total of 23 vaccine injections. Accordingly, the reaction rate was 0.56% among all vaccine doses. The most common reactions were systemic skin reactions (2.7%) consisting of generalized pruritus, diffuse pruritic erythema, urticaria, and maculopapular rash. That was followed by local injection site reaction (0.12%). Anaphylaxis was reported in 4 cases (0.09%) with a mean onset time of 12 ± 6 minutes. One of them had a history of anaphylaxis with 2 drugs, another had venom and food allergy. Three of the subjects had level 2 diagnostic certainty according to the Brighton Collaboration criteria and one had level 3. All anaphylaxis cases were discharged within 24 hours and none of them required intensive care. Our study demonstrated that allergic reactions to CoronaVac were rare and mostly mild. Although anaphylaxis was also rare, the importance of early intervention with close follow-up was once again emphasized.