A vial of the Moderna COVID-19 vaccine is displayed on a counter at a pharmacy in Portland, Ore. on Dec. 27, 2021. U.S. health authorities are facing a critical decision: whether to offer COVID-19 booster shots this fall that better match the omicron variant even though the coronavirus already has spawned still more mutants. Moderna and Pfizer are testing updated booster candidates, and advisers to the U.S. Food and Drug Administration will debate Tuesday, June 28, 2022, if it’s time for a switch, setting the stage for similar moves by other countries. (AP Photo/Jenny Kane, File)