Nickan Research Institute Journal of Parathyroid Disease 2345-6558 10 1 2022 01 01 Gender difference in COVID-19 vaccination; recent concepts e11167 e11167 10.34172/jpd.2022.11167 EN Parisa Soleimani https://orcid.org/0000-0003-3891-1064 Hamid Reza Jahantigh https://orcid.org/0000-0002-0482-7510 Sepideh Yadollahifarsani https://orcid.org/0000-0002-6671-4263 Journal Article 10.34172/jpd.2022.11167 2022 08 27 2022 10 20 Recently, a few different vaccines have been developed to help end the COVID-19 pandemic. These vaccines have made significant progress toward controlling the disease. Multiple factors contribute to the immunity level that these vaccines can stimulate, including sex. The effect of gender on other vaccines’ efficacy has been studied before. The results of these studies are mentioned below. Genetic and hormonal differences between men and women are among the mechanisms suggested for the difference in vaccine efficacy in men and women. Sex hormones play various roles in stimulating or suppressing the immune system. As a result, they are responsible for the intensity and speed at which the vaccine establishes the immune response. In this narrative review study, we discuss the differences in COVID-19 vaccine efficacy and safety between the two genders and the reasons for these differences.