Influenza vaccination among the elderly in Bangkok.

This study aimed to determine the effectiveness of influenza vaccinations among the elderly in Bangkok in reducing influenza-like illness (ILI) and influenza-related complications. Using a non-randomized, controlled, prospective methodology, healthy, active people aged 60 years or more, living in the Bangkok Metropolitan Administration (BMA) area, were studied. The two study cohorts comprised 519 persons in the vaccinated group and 520 in the non-vaccinated group.