[Efficacy and adverse reactions of influenza vaccine in the elderly]

Influenza virus infection is a serious problem in the elderly because of the high pneumonia complication rate and a significant increase in mortality. Influenza vaccine is a method for controlling influenza epidemics in the elderly. The vaccinated elderly showed lower influenza infection rate and had fewer incidences of febrile episodes than did non-vaccinees during epidemics. Significantly, decreased rates of mortality subsequent to influenza epidemics among vaccinated elderly inpatients were also found. The antibody response to influenza vaccine in the elderly is quite comparable to that of younger adults. Adverse reactions to influenza vaccination, including local reaction such as soreness, systemic reactions such as malaise and fever, and allergic reactions, are less frequent in the elderly than in children and younger adults. The currently used inactivated influenza virus vaccine is as safe or safer than other vaccines. Serious adverse effects are unknown in the elderly. The influenza vaccination rate is quite low in Japan when compared with that of other developed countries. To prevent influenza epidemics among the elderly, especially among those who have been institutionalized, influenza vaccine should be promoted more actively.