A smallpox vaccination is prepared at the 28th Medical Operations Squadron Immunization Clinic at Ellsworth Air Force Base, S.D., March 13, 2012. The smallpox vaccine is one of the many mandatory immunizations Airmen are required to receive to ensure they are able to deploy to any location around the globe. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)