Gender and AB0 Blood Type Differences in a Unicentric Group of University Professors in Southern Italy Who Received the Vaxzevria COVID-19 Vaccine: A Cross-Sectional Survey of Vaccine Side Effects, Attitudes, and Hesitation.

Vaccination has been a key protective behavior for COVID-19. This study investigated the clinical status of university professors administered the Vaxzevria COVID-19 vaccine, to monitor for any adverse reaction, and to understand attitude and hesitancy to vaccination. Data were collected through an online survey. The study received approval from the relevant ethics committee "Comitato Etico Campania Sud". Multivariate logistic regressions were used to calculate significant predictors of the outcomes of interest. A gender and AB0 blood type difference in adverse vaccine reactions was found. The multivariate logistic regression model showed that female gender, city residence, blood type A+ and B-, and chronic underlying medical conditions or comorbidities were more strongly implicated in the occurrence of adverse reactions, whereas blood type 0 Rh+ or blood type A Rh- were protective factors of adverse reactions to the Vaxzevria vaccine. Both genders did not show serious adverse reactions to the Vaxzevria vaccine. Based on our results, we are able to support the hypothesis that AB0 blood type and gender difference appear as predictors of Vaxzevria COVID-19 vaccine reactogenicity. Furthermore, in the study population, the degree of concern and hesitation to undergo vaccination was minimal.