GISRS functions through a coordinated effort of National Influenza Centres (NICs) and WHO Collaborating Centres (CCs). NICs collect and analyze clinical specimens from patients with influenza-like illnesses. These data and samples are then shared with CCs, which conduct advanced analyses such as genetic sequencing and antigenic characterization. The information gathered is used to identify circulating strains of the virus and to recommend components for the seasonal influenza vaccine.
