Effects of gender on the efficacy and response to COVID-19 vaccination; a review study on current knowledge

Vaccination is one of the most important public health strategies to reduce mortality and morbidity of various infectious diseases. The COVID-19 pandemic was declared, on March 11, 2020, since then, the virus has spread rapidly, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have played the main substantial role in advancing the management of the COVID-19 pandemic. As is well known, sex/gender-related differences affect vaccine efficacy, response, and acceptability. This review aims to compare the effects of sexual dimorphism and gender-related differences factors on the efficacy, responses, and acceptance of the COVID-19 vaccines. As far as the COVID-19 vaccine effectiveness is concerned, both males and females with the COVID-19 vaccine showed consistent and impressive efficacy; although males showed slightly greater efficacy, there was no significant correlation between the efficacy of the COVID-19 vaccine and their sex or gender differences. Consequently, to reduce adverse reactions in females, sex differences should be considered in the design of the COVID-19 vaccine. It is also essential to conduct pragmatic trials to verify whether sex differences in vaccine response and efficacy vary with age.