High-Dose Flu Vaccine Cuts Older Adult Hospitalizations by 38.5 Percent in 600,000-Person Meta-Analysis

The analysis pooled data from 605,098 participants across North America and Europe, incorporating community-dwelling adults, nursing-home residents, and patients with cardiovascular disease. High-dose vaccine lowered cardiorespiratory hospitalizations by 7.5 percent, pneumonia or influenza admissions by 11.5 percent, and all-cause hospitalizations by 3 percent, with consistent effects in those over 80. No mortality difference reached statistical significance. These absolute reductions translate to thousands of prevented admissions annually given current U.S. flu hospitalization rates exceeding 200 per 100,000 in this age group. Prior individual trials had shown stronger immunogenicity but left policymakers uncertain about real-world hospitalization impact; this synthesis supplies that missing link. Observational data from prior seasons already hinted at similar patterns, yet randomization here minimizes confounding by health status. The findings align with CDC recommendations favoring high-dose or adjuvanted products for seniors since 2022. Remaining questions center on cost-effectiveness thresholds and whether updated strains will preserve the observed relative effectiveness.