Abstract
The increase of the elderly population is a worldwide common phenomenon. According to some projections, in the year 2050 older people will be about 22% of the world population. In Brazil the number of elderly (≥ 60 years of age) increased from 3 million in 1960, and to 7 million by 1975 and 14 million by 2002 (an increase of 500% in just forty years); according to estimates, it will reach 32 million by 2020. This phenomenon is due to advent of antibacterial drugs, large-scale vaccinations and other advances of medical treatment. However, the vaccine efficacy depends on the ability of individuals to exhibit an adequate immune response. This review presents the main effects of immunosenescence in immune response to a vaccine. Furthermore, it discusses strategies that may counteract age-related defects in immune responses to vaccination. The understanding of how immunological memory is affected by ageing, and the introduction of strategies to ameliorate vaccine efficacy in the elderly, might reduce the incidence and the severity of infectious disease and have a strong impact on the quality of life of elderly individuals.
Key words:
Ageing; Immune system; Immunotherapy active; Immunization; Adjuvants immunologic; Communicable diseases; Risk reduction behavior; Incidence; Quality of life; Brazil