Vaccination indications and limits in the elderly.

Infections are a major cause of morbidity and mortality in the elderly. Although vaccination is crucial for preventing infectious diseases, the ability of the elderly to establish an effective immune response to vaccination is much lower compared to the younger population. In most industrialized countries, four vaccines are now recommended for people over 60 years of age: influenza vaccine, pneumococcal vaccine, herpes zoster vaccine, and a vaccine combining tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis. Only the last vaccine provides an adequate antibody response. The influenza and pneumococcal vaccines seem to be able to alleviate disease. The herpes zoster vaccine somewhat prevents reactivation of herpes zoster and decreases the severity of postherpetic neuralgia. Recent technological advances and novel adjuvants are providing new opportunities for improving vaccination of the elderly. Lifelong vaccination schedules should be promoted in order to achieve the herd immunity threshold. Maintaining the health of the population requires moving from a childhood-based vaccination strategy to a more balanced vaccination program throughout life.