Master Sgt. Steven Burns, 28th Medical Operations Squadron NCO in charge of immunizations, fills a syringe with an influenza vaccine at Ellsworth Air Force Base, S.D., March 13, 2012. The immunizations clinic provides vaccinations for more than 1,500 beneficiaries in the Black Hills area. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)