An overview of sex hormones in relation to SARS-CoV-2 infection

Aim: Sex differences in COVID-19 outcomes might be explained from a sex hormones (SexHs) perspective. Materials & methods: PubMed, Scopus, Web of Science, EMBASE and Google Scholar were searched up to March 2021. Results: Based on the literature review, the crosstalk between SexHs (estrogens, progesterone and testosterone), their receptors (estrogen alpha and beta, androgen, and progesterone) and the immune system shaped the sex-related differences in immune responses against COVID-19. Differential production of SexHs over the lifespan (during pregnancy, reproductive years, menopause and andropause) and over different seasons may result in disparities in body response toward COVID-19. Moreover, SexHs-specific differences might affect vaccine efficacy and response to treatment. Conclusion: The roles of SexHs need to be considered in vaccine development and even treatment of COVID-19. Lay abstract: Female and male sex hormones (SexHs) play a pivotal role in the body's defense against viral infections. SexHs and their binding molecules are among the main possible indicators of sex disparities in COVID-19 severity and response to treatment. Changes in the levels of SexHs from the childbearing age to menopause and pregnancy in females, and the aging process in males affect the immune function. This article sheds light on how physiologic hormonal differences in different sexes and in different stages of life affect COVID-19 severity. As a consequence the role of SexHs should be considered in vaccine development and treatment of COVID-19, especially for patients who suffer from hormone-related medical conditions in different stages of life.