Pfizer study says updated COVID boosters rev up protection

Pfizer’s updated COVID-19 booster significantly revved up adults’ virus-fighting antibodies, the company said Friday, releasing early findings from a rigorous study of the new shots.

Booster doses tweaked to target the most common omicron strain rolled out in early September, and the Food and Drug Administration said the latest data should spur more Americans to get one — especially before another expected wave of cases as people travel for Thanksgiving.

Pfizer said people 55 and older who got the omicron-targeting booster had four-fold higher antibody levels than those given an extra dose of the original vaccine.

With many Americans reluctant to roll up their sleeves again, perhaps the better question is how the new booster compares to going without another dose.

A hint: A month after receiving the new booster, antibody levels in people 55 and older had jumped 13 times higher than before the extra dose. Younger adults saw a 9.5-fold jump, Pfizer and its partner BioNTech said. It had been about 11 months since the study participants’ last vaccination.

It’s too soon to know how much real-world protection the antibody boost translates into -- and how long it will last. The results are preliminary, the study is still underway and infection-fighting antibodies naturally wane over time.

Still, the FDA had cleared the updated boosters without first requiring testing in people, basing the decision on studies of a similarly tweaked vaccine — against an earlier omicron strain — rather than the exact recipe.

So the new data “reassures us that this was a good decision to move to this bivalent vaccine,” FDA vaccine chief Dr. Peter Marks told The Associated Press. “Right now is the time for people to consider going out and get the updated” booster.

Health experts say it's shaping...