Influenza vaccination in the elderly as a strategy to improve vaccine effectiveness

Abstract

Evaluation of: Nichol KL, Nordin JD, Nelson DB, Mullooly JP, Hak E: Effectiveness of influenza vaccine in the community-dwelling elderly. N. Engl. J. Med. 357(14), 1373–1381 (2007). Recent publications have questioned the benefit of influenza vaccination in the older adult population. To address this issue, Nichol et al. reported a study of 713,872 person-seasons over ten influenza seasons, which showed that influenza vaccination was associated with significant reductions in influenza-related hospitalizations and deaths among community-dwelling older adults. The comprehensive database ensured adequate baseline and follow-up data for annually defined influenza seasons. This analytic method reduces the potential of survivor bias when the baseline is established in the summer months preceding the influenza season, as has been used in other studies. The results were further supported by a sensitivity analysis using a hypothetical confounder to detect a healthy vaccinee bias and showed that the hospitalization...