[Age-related decline in vaccination efficacy: The potential role of myeloid derived suppressor cells.]

Infectious diseases in older people are much more frequent, and mortality from them is higher than in young people. Vaccination is the most effective and least expensive preventative measure for a number of infectious diseases. However, vaccines that are effective in young people are often ineffective in older people over 65, which is a result of a gradual decrease in the functional capacity of the immune systems, which occurs with age, and is called «immunosenescence». Age-related changes in the cellular and humoral immunity worsen the primary response to vaccines and weaken the development of long-term immunological memory. Recent studies suggest that one of the possible causes of the occurrence and maintenance of «immunosenescence» may be myeloid-derived suppressor cells (MDSCs). These cells have been shown to inhibit the functions of innate and adaptive immunity cells through a number of mechanisms. In this review, we provide information that emphasizes the role of MDSCs in inhibiting the immune response to vaccines during aging, and also substantiates possible ways to overcome this immunological obstacle.