Influenza vaccination in elderly people and its efficacy - Prevention and control of influenza infections in nursing homes

Elderly people aged 65 or older compose a high risk group who are at high risk for complications, and influenza vaccination is strongly recommended for those persons and health care workers (HCWs) who look after these elderly persons. There is no doubt about the effect of the vaccine for preventing pneumonia, hospitalization and death, but the efficacy for lowering the incidence of influenza-like illness (ILI) varies considerably among studies, provably due to character of influenza virus itself and also research methods of the vaccine efficacy. Now, introduction of several research methods which reduced the bias revealed clearly the efficacy for preventing ILI. Furthermore, several other reports indicate that high vaccination rate in both residents and HCWs reduced the risk for institutional outbreaks by inducing herd immunity. Vaccination is an important basic strategy against influenza infections, and furthermore the combination of vaccine and anti-influenzal drugs (amantadine or neuramininase inhibitors) will be the strategy of choice in near future.