Interim vaccine effectiveness against influenza virus among outpatients, France, October 2025 to January 2026

Abstract

In Europe, the 2025/26 seasonal influenza epidemic started in October 2025. Co-circulation of A(H3N2) and A(H1N1)pdm09 was observed in several countries including France. We estimated early vaccine effectiveness (VE) against influenza virus in French outpatients (5,451 positives/18,816 negatives). A significant VE across all age groups was measured: 28% (95% CI: 17–37) for those aged ≥ 65 years, 45% (95% CI: 36–53) for 18–64-year-olds and 57% (95% CIs: 29–74) for 0–17-year-olds. Reinforcing vaccination uptake is warranted.