The Global Influenza Hospital-based Surveillance Network (GIHSN) is based on public-private partnerships constituted by FISABIO (Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana), Sanofi Pasteur, Fondation Mérieux and multiple country sites affiliated with health authorities. Each site supervises a network of hospitals. This hospital active surveillance network has been put in place to better understand global influenza epidemiology. Through its broad geographical coverage, standardization of data collection, and its expected sus

tainability over sequential influenza seasons; the network focuses on estimating the incidence of severe influenza disease and the incidence of the disease attributable to each strain. In addition, it provides a framework for estimating effectiveness of seasonal influenza vaccines in prevention of severe cases in various age and risk groups.