U.S. Air Force Staff Sgt. Cliff Cooke, 52nd Logistics Readiness Squadron quality assurance and customs technician from El Mirage, Ariz., receives a flu vaccination during a point of distribution medical exercise Oct. 16, 2013. The 52nd Medical Group aimed to provide flu vaccinations for the base's active duty and dependent or beneficiary civilian populations. (U.S. Air Force photo by Airman 1st Class Gustavo Castillo/Released)