U.S. Air Force Staff Sgt. Keneisha Fuller, 633rd Surgical Operations Squadron aerospace medicine service technician, administers an influenza vaccine to Jean Michel, Air Combat Command chief of Airmen and family readiness services, during a mass prophylaxis exercise at Langley Air Force Base, Va., Nov. 17, 2011. The group vaccinated 224 patients during the exercise. (U.S. Air Force photo by Airman 1st Class Racheal Watson/Released)