Immune Cells, Gut Microbiota, and Vaccines: A Gender Perspective

Abstract

The development of preventive and therapeutic vaccines has played a crucial role in preventing infections and treating chronic and non-communicable diseases, respectively. For a long time, the influence of sex differences on modifying health and disease has not been addressed in clinical and preclinical studies. The interaction of genetic, epigenetic, and hormonal factors plays a role in the sex-related differences in the epidemiology of diseases, clinical manifestations, and the response to treatment. Moreover, sex is one of the leading factors influencing the gut microbiota composition, which could further explain the different predisposition to diseases in men and women. In the same way, differences between sexes occur also in the immune response to vaccines. This narrative review aims to highlight these differences, focusing on the immune response to vaccines. Comparative data about immune responses, vaccine effectiveness, and side effects are reviewed. Hence, the intricate interplay between sex, immunity, and the gut microbiota will be discussed for its potential role in the response to vaccination. Embracing a sex-oriented perspective in research may improve the efficacy of the immune response and allow the design of tailored vaccine schedules.

Keywords: gender; gut microbiota; hormones; immune cells; vaccines.

Figure 1

Since the first definition of “gender medicine” came out in the early nineties, the scientific community has investigated the impact of sex on physiology, physiopathology, and clinical features of disease in order to provide evidence-based therapeutic decisions. A novel appealing chapter within gender medicine is “gender vaccinology”, which explores the benefits and risks of vaccination in both men and women with the aim of encouraging strategies of health promotion.