(FILES) In this file photo a lab technician sorts blood samples for Covid-19 vaccination study at the Research Centers of America in Hollywood, Florida on August 13, 2020. The United States hopes to begin a sweeping program of Covid vaccinations in early December, the head of the government coronavirus vaccine effort said on November 22, 2020. "Our plan is to be able to ship vaccines to the immunization sites within 24 hours of approval" by the US Food and Drug Administration, Moncef Slaoui t