The Pfizer Global Supply Kalamazoo manufacturing plant is shown in Portage, Michigan, Friday, Dec. 11, 2020. The U.S. gave the final go-ahead Friday to the nation's first Covid-19 vaccine, marking what could be the beginning of the end of an outbreak that has killed nearly 300,000 Americans. (AP Photo/Paul Sancya)(AP PHOTO/PAUL SANCYA)