With a retrospective nationwide cohort study in the Netherlands over 1992-2003, using mortality and viral surveillance data, the aim was to assess by means of rate difference methods the influenza-associated mortality in the elderly before and after the introduction of a nationwide influenza vaccination program in 1996 (vaccination coverage raised from below 50 to 80%). The average annual influenza-associated mortality declined in the years before and after the introduction from 131 to 105 per 100,000 persons (relative risk 0.80). The decline was largest in the age group 65-69 years (relative risk 0.54) and less in those aged 75 years and older. Validation by Serfling-type regression analysis revealed similar results. In conclusion, routine influenza vaccination among Dutch elderly was associated with a significant decrease in influenza-associated mortality, notably in those aged 65-69 years.
Bibliographical noteFunding Information:
Dr. Nichol reports having served as a consultant to the influenza vaccine manufacturers Sanofi Pasteur, MedImmune, GSK, and Novartis. Dr. Nichol has received or will receive grant support from Sanofi Pasteur and GSK. This study was funded by the Health Council of the Netherlands.
- Influenza vaccine