The U.S. Department of Health and Human Services, CDC, state and local health departments, and other partners will observe National Influenza Vaccination Week during December 4-10, 2016, with educational and promotional activities across the country. Beginning in 2005, National Influenza Vaccination Week was established to highlight the importance of annual influenza vaccination and to foster greater use of influenza vaccine during the months of December, January, and beyond. Last season, almost half (45.6%) of the U.S. population aged ≥6 months are estimated to have received vaccination against influenza. This is a small decline of 1.5% since the previous season (47.1%), but close to what was seen during the 2013-2014 (46.2%).