How effective are vaccines in preventing influenza, influenza-like illness, hospital admissions, complications and mortality in the elderly (65 years or older)?
The results were mostly based on non-experimental (observational) studies, which were at greater risk of bias, as not many good quality trials were available (only one randomised controlled trial). Studies done in residents of care homes often indicate the inevitably improvised nature of efforts to study the effect of vaccination during an epidemic. The resident population is usually more homogeneous than that in the community: older, with similar viral exposure and risk levels.
Influenza vaccination of elderly individuals is recommended worldwide, as people aged 65 and older are at a higher risk of complications, hospitalisations and deaths from influenza. In the year 2000, 40 out of 51 high-income or middle-income countries recommended vaccination for all persons aged 60 or 65 or older.¹ 1. van Essen GA. Vaccine 2003;21:1780–5.