The Global Influenza Surveillance and Response System (GISRS) is a global network of laboratories that has the purpose to monitor the spread of influenza with the aim to provide the World Health Organization with influenza control information. It was established in 1952 to conduct global influenza surveillance and to inform vaccine development. GISRS is coordinated by WHO and endorsed by national governments. Several millions of respiratory specimens are tested by GISRS annually to monitor the spread and evolution of influenza viruses through a network of laboratories in 127 countries representing 91% of the world's population. As well as human viruses, GISRS monitors avian and other potentially zoonotic influenza viruses. GISRS operates FluNet, an online tool used for virological surveillance of influenza.