US renews push for COVID boosters as data show they protect

Americans who got the updated COVID-19 booster shots are better protected against symptomatic infection than those who haven’t — at least for now, U.S. health officials said Tuesday.

Updated boosters rolled out by Pfizer and rival Moderna in September have been a hard sell for vaccine-weary Americans. Only about 13% of U.S. adults so far have gotten a “bivalent” shot that targets the omicron strain as well as the original coronavirus. On Tuesday, White House officials announced a renewed push for more Americans to get the latest shots.

In the first look at the new shots' real-world effectiveness, the Centers for Disease Control and Prevention tracked people with coronavirus-like symptoms who sought testing at drugstores around the country between September and early November. Researchers compared the vaccination status of those who wound up having COVID-19 with those who didn’t.

The new omicron-targeting booster added 30% to 56% protection against symptomatic infection, depending on how many prior vaccinations someone had, how long ago and their age, the CDC concluded.

People getting the greatest benefit are those who'd never had a prior booster, just two doses of the original COVID-19 vaccine at least eight months earlier, said CDC's Dr. Ruth Link-Gelles, who led the study.

But even people who got a summertime booster of the original vaccine before seeking the new fall formula were 30% to 40% more protected than if they’d skipped this latest shot, she said.

“We think about it as the additional benefit or incremental benefit of getting one more dose, and in this case that one more dose is a bivalent,” Link-Gelles said.

The updated boosters target the BA.5 omicron strain that until recently was the most common type. The original COVID-19 vaccines have offered strong...