Sex and Gender Impact Immune Responses to Vaccines Among the Elderly

Abstract

In response to the recommended vaccines in older-aged individuals, sex differences occur in response to those that protect against influenza, tetanus, pertussis, shingles, and pneumococcal infections. The efficacy of vaccines recommended for older-aged adults is consistently greater for females than for males. Gender differences as well as biological sex differences can influence vaccine uptake, responses, and outcome in older-aged individuals, which should influence guidelines, formulations, and dosage recommendations for vaccines in the elderly.

FIGURE 1.

Among adults, susceptibility to infection increases with older age For infectious diseases in which vaccines are available, vaccines are the primary prophylactic treatment for the prevention of disease. Antibody responses as well as the efficacy of vaccines decrease with older age and to a greater extent among males than females. In addition to immunological changes that occur with older age, endocrinological changes occur in both males and females, in which both estrogen and testosterone levels decline, which may contribute to increased susceptibility to infections and reduced efficacy of vaccines in older-aged individuals.