A dose of a Pfizer COVID-19 vaccine is prepared at Lurie Children's hospital, Nov. 5, 2021, in Chicago. Three new U.S. studies offer more evidence that the COVID-19 vaccines are standing up to the omicron variant, at least among people who have received booster shots. The Centers for Disease Control and Prevention released the studies, Friday. Jan. 21, 2022. (AP Photo/Nam Y. Huh, File)