Repeat vaccination and influenza vaccine effectiveness

Influenza vaccine effectiveness estimates are estimates of the reduction in risk of influenza conferred by influenza vaccination and inform individuals and public health agencies about the benefits of vaccination. In many vaccine effectiveness studies, estimates are presented of the reduction in risk of medically-attended influenza virus infection among people who have been vaccinated versus those who have not in that season. The systematic review and meta-analysis by Elenor Jones-Gray and colleagues 1 Jones-Gray E Robinson EJ Kucharski AJ Fox A Sullivan SG Does repeated influenza vaccination attenuate effectiveness? A systematic review and meta-analysis. Lancet Respir Med. 2022; (published online Sept 21.)https://doi.org/10.1016/S2213-2600(22)00266-1 PubMed Google Scholar examines the important question of whether vaccination history can modify the vaccine effectiveness in the current year. Does repeated influenza vaccination attenuate effectiveness? A systematic review and meta-analysisOur estimates suggest that, although vaccination in the previous year attenuates vaccine effectiveness, vaccination in two consecutive years provides better protection than does no vaccination. The estimated effects of vaccination in the previous year are concerning and warrant additional investigation, but are not consistent or severe enough to support an alternative vaccination regimen at this time. Full-Text PDF Open Access