The Global Influenza Hospital Surveillance Network (GIHSN) has established a prospective, active surveillance, hospital-based epidemiological study to collect epidemiological and virological data for the Northern and Southern Hemispheres over several consecutive seasons. It focuses exclusively on severe cases of influenza requiring hospitalization. A standard protocol is shared between sites allowing comparison and pooling of results. During the 2014-2015 influenza season, the GIHSN included seven coordinating sites from six countries (St. Petersburg and Moscow, Russian Federation; Prague, Czech Republic; Istanbul, Turkey; Beijing, China; Valencia, Spain; and Rio de Janeiro, Brazil). Here, we present the detailed epidemiological and influenza vaccine effectiveness findings for the Northern Hemisphere 2014-2015 influenza season.

D 1 Ivanovsky Institute of Virology FGBC N F Gamaleya FRCEM Ministry of Health of Russian Federation Moscow Russian Federation Russia

Division of Infectious Disease Key Laboratory of Surveillance and Early Warning on Infectious Disease Chinese Center for Disease Control and Prevention Beijing China

Foundation for the Promotion of Health and Biomedical Research in the Valencia Region FISABIO Public Health Avda Catalunya 21 46020 Valencia Spain

National Influenza Reference Laboratory Istanbul Faculty of Medicine Istanbul University Istanbul Turkey

National Institute of Public Health Prague Czech Republic

Research Institute of Influenza Saint Petersburg Russian Federation Russia

School of Public Health Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong Special Administrative Region China

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