Immunological Aspects and Gender Bias During Respiratory Viral Infections Including Novel Coronavirus Disease-19 (COVID-19): A Scoping Review

This scoping review examines the immunological differences between genders in respiratory viral infections, including COVID-19, and suggests that males are more likely to experience severe disease due to factors like hormone levels, androgen receptors, and gene variants. Estrogen appears to play a key role in the stronger immune response observed in females, influencing cellular and humoral immunity, and potentially reducing the severity of infections. A meta-analysis of 33,970 patients showed that men had a 1.5 times higher incidence of venous thromboembolic events than women among hospitalized COVID-19 patients. Women were found to have better T cell activation, which correlates with less severe disease outcomes. The review also discusses the potential benefits of vitamin D supplementation and hormone replacement therapy in managing COVID-19. It concludes that sex hormones significantly modulate immune responses, leading to gender-based differences in susceptibility and outcomes of respiratory viral infections, and calls for further research to inform vaccine development and treatment strategies.