Staff Sgt. Penny Witt, 436th Medical Operations Squadron medical technician, administers the influenza vaccine to Senior Airman Catrina Celestine, 436th Aerial Port Squadron logistics manager, Oct. 10, 2013, at the 436th Medical Group Clinic on Dover Air Force Base, Del. The 436th Medical Group inoculated active duty airman to prepare for the upcoming flu season. (U.S. Air Force photo/Airman 1st Class William Johnson)