FILE – In this Jan. 12, 2021, file photo resident of Harmony Court Assisted Living receives the Pfizer COVID-19 vaccine in Jackson, Miss. The U.S. vaccination drive against COVID-19 stood on the verge of a major new phase as government advisers Thursday, Sept. 23, recommended booster doses of Pfizer’s vaccine for millions of older or otherwise vulnerable Americans — despite doubts the extra shots will do much to slow the pandemic. (AP Photo/Rogelio V. Solis, File)