U.S. Air Force Col. Jack Gardner, 99th Air Base Wing vice commander, and Chief Master Sgt. Emilio Hernandez, U.S. Air Force Warfare Center command chief, check in to receive their COVID-19 vaccines at Nellis Air Force Base, Nevada, Jan. 5, 2021. The first phase of vaccines were administered to first responders, mission-essential personnel, deploying forces and individuals with serious illnesses. (U.S. Air Force photo by Senior Airman Dwane R. Young)