PHILADELPHIA (April 2, 2021) Sgt. Maj. Troy E. Black, the 19th Sergeant Major of the Marine Corps, greets U.S. Marines and Sailors during a tour of the state-run, federally-supported Center City Community Vaccination Center in the Pennsylvania Convention Center in Philadelphia, April 2, 2021. Marines and Sailors with Combat Logistics Battalion 22, from Camp Lejeune, North Carolina, are deployed in support of the federal vaccine response. U.S. Northern Command, through U.S. Army North, remains committed to providing continued, flexible Department of Defense support to the Federal Emergency Management Agency as part of the whole-of-government response to COVID-19. (U.S. Marine Corps photo by Lance Cpl. Zachary Zephir)