FDA Approves More Boosters, Says It's Ok to Mix and Match COVID-19 Shots

The Food and Drug Administration has approved two more types of COVID-19 booster shots and even says it's ok to mix and match different vaccines from different pharmaceutical companies.

That authorization comes with the approval of boosters for the Moderna and Johnson & Johnson vaccines. Authorities already approved a booster for the Pfizer vaccine for many Americans last month.

"We now know that J&J wanes more quickly than the mRNA vaccines, and being able to give more options to patients is important," said John Brownstein, Ph.D., of Boston Children's Hospital.

There is some evidence that a booster with an mRNA vaccine will provide more benefits for people who received the one-shot Johnson & Johnson.

A limited study found that an additional dose of the same Johnson & Johnson vaccine boosted antibodies by four times.

Boosting the J&J shot with Pfizer caused antibodies to jump 35 times, and a Moderna booster increased antibodies 76 times. 

Still, some who received the J&J vaccine want to keep the same booster brand. "I'd rather stay with one course and just keep it that way," said Jonathan Bierig, who received the Johnson & Johnson vaccine. 

Vaccinations are lowering the number and severity of COVID cases nationwide. A CDC analysis released Tuesday showed the Pfizer vaccine 93 percent effective at preventing hospitalizations of 12- to 18-year-olds.

Overall, new cases are on the decline in the U.S., but cases and hospital admissions are on the rise in 10 states that experience colder climates as more people gravitate indoors.

"I really do not want to see another horrific fall-winter wave like we saw last year, and I think it's possible," said Peter Hotez, Ph.D., of Baylor College of Medicine. 

Meanwhile, experts want more intense research of new COVID variants. At least six percent of cases in the United Kingdom are what's known as AY.4.2, a descendant of the Delta variant. COVID deaths spiked at their highest level since March in the U.K.  

U.S. researchers are also tracking that sub-variant. "From the data that I've seen, cases of the AY.4.2 have been seen in about five states, maybe about seven cases total," said Julie Hirschhorn, Ph.D., the molecular pathology lab director at the Medical University of South Carolina. 

Scientists are seeking to learn if it's more easily spread. "We need to remain vigilant," said Dr. Richard Besser, the CEO of the Robert Wood Johnson Foundation. "Whether this variant will turn out to be a problem or not, until this is controlled everywhere in the world, we all remain at risk."

Going forward, a CDC advisory panel will debate and vote on the mixing of vaccine booster shots on Thursday, with the CDC director making her final recommendations shortly after that.