Early estimates of 2016/17 seasonal influenza vaccine effectiveness in primary care in France

International audienceBackground: The ongoing 2016/17 influenza epidemic in France is characterized by the circulation of A(H3N2) viruses, known to cause more severe illness among at risk populations.Objectives: The purpose of our study was to provide early influenza vaccine effectiveness (IVE) estimates for the ongoing influenza epidemic in France and compare these estimates over the six post-pandemic IVE.Study design: We used clinical and virological data collected in primary care by the French Sentinelles network. IVE in preventing influenza infection was estimated by the test-negative design method. The screening method was used to estimate IVE in preventing medically-attended influenza-like illness among target groups (