The U.S. is expanding COVID-19 boosters as it confronts the omicron surge. The Food and Drug Administration on Monday allowed extra Pfizer shots for children as young as 12. Boosters already are recommended for everyone 16 and older, and the FDA says they’re also warranted for 12- to 15-year-olds. The FDA also said everyone eligible for a Pfizer booster can get one as early as five months after their last dose rather than six months. But the move, coming as classes restart after the holidays, isn’t the final step. The Centers for Disease Control and Prevention must decide whether to recommend boosters for the younger teens.