Research reveals effectiveness of repeated influenza vaccination

New research reveals that repeated vaccination for influenza (among older adults) was twice as effective in preventing severe influenza compared with nonsevere influenza in patients who were admitted to hospital.

The researchers enrolled 130 inpatients with severe and 598 with nonsevere influenza who were matched to 333 and 1493 controls, respectively. Compared with patients who were unvaccinated in the current and 3 previous seasons, adjusted effectiveness of influenza vaccination in the current and any previous season was 31% (95% confidence interval [CI] 13%–46%) in preventing admission to hospital for nonsevere influenza, 74% (95% CI 42%–88%) in preventing admissions to ICU and 70% (95% CI 34%–87%) in preventing death.

These authors argue that the findings reinforce recommendations for annual vaccination for influenza in older adults.