Immune Responses to Viruses and Vaccines Differ Between Men and Women: Sex hormones can trigger differential responses between females and males to infectious agents and vaccines

Human sex differences extend beyond anatomy to encompass important immune system functions, predisposing men and women to respond differently to infectious diseases. For instance, estrogens tend to promote stronger inflammatory, cellular, and humoral immune responses in women than men. While robust immune responses to pathogens can benefit the host, overexuberant inflammatory responses can damage host tissues—predisposing women more than men to develop immunopathologies, comorbidities, autoimmune disorders, and adverse reactions to vaccines, among other deleterious effects.