FDA authorizes Pfizer, Moderna's updated COVID vaccine boosters

The US Food and Drug Administration on Wednesday authorized updated Covid-19 vaccine booster shots from Moderna and Pfizer. This is the first time updated Covid-19 vaccines have received emergency use authorization in the United States.

Both are bivalent vaccines that combine the companies' original vaccine with one that targets the BA.4 and BA.5 Omicron sublineages. Both companies submitted applications to the FDA for emergency use authorization for their updated vaccines last week.

Pfizer's updated vaccine is a 30-microgram dose authorized for people age 12 and older. Moderna's updated vaccine is a 50-microgram dose authorized for people age 18 and older.

The shots can be administered only after they're recommended by the US Centers for Disease Control and Prevention. The CDC's vaccine advisory group is scheduled to vote Thursday on whether to support recommending the boosters for use.

WBZ-TV's Dr. Mallika Marshall expects the CDC to take quick action.

"Assuming they vote favorably, the CDC Director will then have to formally sign off," she said. "When that happens, which she is likely to do rather quickly, these boosters could become available within the next week or so."    

Dr. Mallika says boosters could be an important tool in preventing another wave of COVID cases.

"Even those of us who are fully vaccinated and have received one or even two boosters are not optimally protected against getting infected with the Omicron variant, even though we're still well protected against severe illness," she said. "But preliminary data on these newly formulated boosters have shown that they can trigger a strong antibody response not only to the original coronavirus but to the Omicron subvariants, which have been responsible for the vast majority of cases in recent months. So, if we can immunize millions of Americans in the coming weeks, we could reduce the number of infections and help curb the surge in cases expected this winter."