Rachel Brittain, 12, from Newport News, Va., receives a flu shot from U.S. Air Force Senior Airman Justin Johannes, 633rd Medical Operations Squadron immunizations backup technician, at Langley Air Force Base, Va., Nov. 25, 2013. Vaccinating children helps protect against various diseases, and is required to use base facilities such as the Child Development Center. (U.S. Air Force photo by Senior Airman Connor Estes/Released)