Senior Airman Megan Knutson administers a vaccination to an airman. U.S. Air Force Senior Airman Megan Knutson, a medical technician assigned to the 28th Medical Operations Squadron, administers a vaccination to an airman at Ellsworth Air Force Base, S.D., on May 13, 2009. The immunizations clinic provides vaccinations for more than 1,500 beneficiaries in the South Dakota's Black Hills area. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 333343-M-HII47-426.jpg Photo Gallery