Pfizer Study Finds Big Rise in Immunity From COVID Booster

FRIDAY, Nov. 4, 2022 (HealthDay News) -- Getting an updated booster for COVID-19 is likely to boost protection substantially, according to a new study released by drug company Pfizer on Friday.

The news affirms a decision by the U.S. Food and Drug Administration to OK the bivalent booster without first requiring human testing, the Associated Press reported.

The booster was tweaked to target the now dominant omicron variant along with the original virus, and was cleared based on studies of a similar shot targeting an earlier variant, according to the AP.

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 AP. "Right now is the time for people to consider going out and get the updated" booster, he said.

To study the new booster, Pfizer compared results for adults who received it to those who received a fourth dose of its original COVID vaccine.

The new booster combines vaccines for the original COVID-19 strain and the now-dominant omicron BA.5 strain.

The results showed that people 55 and older who received Pfizer's new bivalent vaccine had antibody levels four times as high as those who given another dose of the original vaccine, the AP reported.

Those 55 and up who received the new booster had antibody levels 13 times higher than before getting the shot. Younger adults who had not received a vaccine in about 11 months also saw improved antibodies, about a 9.5-fold increase.

Pfizer said it's too soon to know how much real-world protection the antibodies provide and how long the protection will last. The study is continuing.

While vaccine effectiveness tends to wane with time and the emergence of new variants, the original COVID shots still offer strong protection against severe illness and death, especially in younger and healthier people, the AP reported.

Since September, 26.3 million Americans have received an updated booster, according to the U.S. Centers for Disease Control and Prevention. Public health officials are encouraging others to do so.

This winter could bring the spread of a trio of serious viruses -- another COVID-19 wave, an unusually early and harsh flu season, and the spread of respiratory virus RSV, the AP reported.

While Pfizer's vaccine is available for those ages 5 and older, a similar bivalent vaccine from Moderna is for those 6 and older.

More information

The U.S. Centers for Disease Control and Prevention has more on COVID-19 vaccines and boosters.

SOURCE: Associated Press, Nov. 4, 2022