Tweaked COVID boosters in US must target newer omicron types

U.S. regulators told COVID-19 vaccine makers Thursday that any booster shots tweaked for the fall will have to add protection against the newest omicron relatives.

The Food and Drug Administration said the original vaccines would be used for anyone still getting their first series of shots. But with immunity waning and the super-contagious omicron family of variants getting better at dodging protection, the FDA decided boosters intended for fall needed an update.

The recipe: Combination shots that add protection against the omicron relatives named BA.4 and BA.5 to the original vaccine. Those mutants together now account for just over half of new U.S. infections.

It’s still a gamble as there’s no way to know if an omicron relative still will be a threat as cold weather approaches or if a newer mutant will take its place. And the current Pfizer and Moderna vaccines still offer strong protection against COVID-19′s worst outcomes as long as people have gotten already recommended boosters.