Sex in infectious diseases-How sex differences influence the immune response to infections

The humoral and cellular immune responses to antigen stimulation, vaccinations and infections differ between women and men. Genetic, epigenetic and hormonal factors contribute to the sex-specific immunity. The expression of genes on the X-chromosome and the effect of sex hormones substantially influence the immune defence against infections. Females show stronger cellular and humoral immune responses to infections than males, but the enhanced immune response often leads to aberrant inflammatory reactions and autoimmune diseases. Men are principally more prone to bacterial, viral and fungal infections and more often show severe disease courses. In contrast, a more reactive female immune system results in significantly more adverse reactions to vaccinations. In order to be able to better identify the multiple sex-specific that have an influence on the immune system, sex-specific differences should be investigated in a differentiated way. The better understanding of the sex-specific differences in the immune response will have a long-term influence on the prevention, diagnostics and treatment of infectious diseases, and will ultimately contribute to improving healthcare of both women and men.