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

20266 citationsJournal Articlediamond Open Access

Authors

Allan De Clercq · Université de Lille

François Blanquart · Centre National de la Recherche Scientifique

Vincent Vieillefond · Honeywell (France)

Benoit Visseaux · Virbac (France)

Alexandra Jacques · Georgia Tech Lorraine

Stéphanie Haïm‐Boukobza · Virbac (France)

Valentin Wehrle

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.

Topics & Keywords

Influenza Virus Research Studies Respiratory viral infections research Immune responses and vaccinations

UN Sustainable Development Goals

Good health and well-being

Publication Details

Published in: Eurosurveillance

Volume 31, Issue 2

DOI: 10.2807/1560-7917.es.2026.31.2.2500992

Field-Weighted Citation Impact: 200.08