Pfizer study finds updated COVID boosters improve protection

Pfizer’s updated COVID-19 booster has dramatically accelerated adults’ anti-virus antibodies, the company said on Friday, releasing early results from a rigorous study of the new vaccines.

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

Pfizer said people 55 and older who received the omicron-targeted booster had antibody levels four times higher than those who received an additional dose of the original vaccine.

With many Americans reluctant to roll up their sleeves, perhaps the better question is how the new booster compares to not having another dose.

Hint: A month after receiving the new booster, antibody levels in people 55 and older had jumped 13 times more than before the extra dose. Young adults saw a 9.5-fold jump, Pfizer and partner BioNTech said. It had been approximately 11 months since the study participants were last vaccinated.

It’s too early to tell how much real-world protection translates to stronger antibodies — and how long that will last. The results are preliminary, the study is still ongoing and anti-infective antibodies naturally decline over time.

Yet the FDA had cleared the updated recalls without first requiring human testing, basing its decision on studies of a similarly modified vaccine — against an earlier omicron strain — rather than the exact recipe. .

So the new data “reassures us that it was a good decision to switch 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 getting the updated booster.”

Health experts say winter is going to be harsh. Flu season is starting unusually early and harsh, children’s hospitals are filled with another respiratory disease called RSV, and COVID-19 cases are expected to rise again with holiday gatherings.

The original COVID-19 vaccines still offer strong protection against serious illness and death, especially in younger, healthier people who have had at least one booster – a reason for anyone who hasn’t received their first round of vaccines to do so. But the effectiveness decreases as new mutants emerge and more time passes since someone’s last shot.

The updated doses are combination injections, designed to provide increased protection against the original strain of coronavirus and the dominant strain BA.5. The Pfizer shot is available to anyone 5 years or older. Moderna’s version of the updated booster is for ages 6 and up.

About 26.3 million Americans have received an updated reminder since their rollout in early September, according to the Centers for Disease Control and Prevention.

Some small studies have recently raised questions about the benefits that updated boosters will provide rather than just getting another dose of the original vaccine.

Pfizer’s early findings compared several dozen younger and older adults who received the bivalent booster with a group that received a fourth dose of the company’s original vaccine.


The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute Department of Science Education. The AP is solely responsible for all content.

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