CHINHAE, Republic of Korea (Jan. 7, 2021) U.S. Army Sgt. 1st Class Ronald Railing administers the COVID-19 vaccine to Quartermaster 2nd Class Crassandra Hoover. Soldiers assigned to the 549th Medical Hospital Center, 65th Medical Brigade administered the COVID-19 vaccine, on a completely voluntary basis, to U.S. Navy Sailors who were identified as front line personnel by their commands. (U.S. Navy photo by Mass Communication Specialist 2nd Class Michael Chen)