U. S. Air Force Staff Sgt. Morgan Mack, left, 423rd Medical Squadron noncommissioned officer in charge of immunization, administers the COVID-19 vaccine to a 423rd Security Forces Squadron Airman at Royal Air Force Alconbury, England, Jan. 5, 2021. 501st Combat Support Wing first responders were prioritized to receive the vaccine based on the guidance from the Centers for Disease Control and Prevention as well as the DoD COVID Task Force’s assessment of unique DoD mission requirements. (U.S. Air Force photo by Senior Airman Jennifer Zima)