U.S. Air Force Master Sgt. Gerald Allen, 51st Civil Engineer Squadron assistant chief of fire protection, receives the first dose of the Moderna COVID-19 vaccine at Osan Air Base, Republic of Korea, Dec. 29, 2020. The 51st Medical Group has developed a prioritized personnel distribution plan for members to voluntarily receive the vaccine beginning Dec. 29. They will continue to identify recipients in the future as more doses become available. (U.S. Air Force photo by Staff Sgt. Betty R. Chevalier)