Demographic evidence of sex differences in vulnerability to infectious diseases.

TO THE EDITOR—The journal’s recent supplement on sex differences in susceptibility and response to infectious diseases was an excellent initiative for promoting research on a neglected topic of major interest. If, in general, males show a higher susceptibility to many infectious diseases, the reviews displayed a number of infectious and autoimmune diseases for which females are more vulnerable. Differential vulnerability between males and females may come from exposure, infection (local or systemic), immune reaction, or a combination of these factors. Evidence came mainly from medicine, epidemiology (direct observation), and biology (animal models and in vivo observation). I address another dimension: demographic evidence.