FDA Authorizes Updated COVID-19 Vaccines Targeting Omicron Subvariant

WASHINGTON — The Food and Drug Administration on Wednesday authorized updated COVID-19 booster shots specifically targeting a subvariant of omicron.

The agency approved two options aimed at the BA.5 subvariant of omicron that is now dominant in the U.S.: one made by Pfizer and its German partner BioNTech for use in people as young as 12; the other, manufactured by Moderna, for those 18 and older.

Wednesday’s authorization allows the use of the new bivalent formulations of the vaccines as a single booster dose at least two months following primary or booster vaccination.

 Both represent the first major redesign of the COVID vaccines since they were initially injected into arms in December 2020.

The updated boosters include an mRNA component of the original strain to provide an immune response that is broadly protective against COVID-19 and an mRNA component in common between the omicron subvariants BA.4 and BA.5 lineages to provide better protection against COVID-19 caused by the omicron variant. 

The BA.4 and BA.5 lineages of the omicron variant are currently causing most cases of COVID-19 in the U.S. and are predicted to circulate this fall and winter. 

The doses can be given at least two months after people last received a booster dose or completed their initial series of vaccinations.

“As we head into fall and begin to spend more time indoors, we strongly encourage anyone who is eligible to consider receiving a booster dose,” Dr. Robert M. Califf, the F.D.A. commissioner, said in a written statement. 

He added that the newly formulated vaccine would “provide better protection against currently circulating variants.”

But the approval of the new vaccines didn’t come without some push back from members of the FDA advisory committee that reviewed their efficacy.

The concern mainly revolves around the speed at which the new vaccines were turned around — the FDA advised the companies only two months ago on the formulation that they should adopt for the new vaccines — and the resulting lack of human trials.

Both Pfizer and Moderna went to federal regulators this summer with more limited data on the redesigned boosters than a traditional review process would call for — instead of human trials, they presented the outcome of tests of the new vaccines on mice.

Last week, Dr. Paul Offit, a member of the FDA advisory committee, told The Well News he was, at best, skeptical of the data the pharmaceutical companies have presented. 

“As a famous vaccinologist at the Wistar Institute says: ‘Mice lie and monkeys exaggerate,’” he said, referring to the independent, nonprofit research institution in Philadelphia.

“You can’t use mice to predict events in people. You just can’t,” Offit said. “I mean, let me put it this way, if mouse studies were predictive of outcomes in people, we would have had an AIDS vaccine 30 years ago.

“The bottom line is, mice aren’t people. They have a different genome … and while they help sort of point you in the right direction … I just don’t think tests on mice can be used as a proof that something is going to be valuable that you’re about to give to millions of people. I just don’t think that’s adequate. And I think that the American public deserves more data than what we’ve been given,” he said.

But others argue that because the coronavirus is evolving so quickly, human trials would be out of date long before a formal authorization could be handed down.

According to the Centers for Disease Control and Prevention, the number of COVID cases, deaths and hospitalizations are all trending lower.

As of Wednesday morning, the daily average of new cases wass 82,475, with the average daily number of deaths being 387, and the average daily new admissions to hospitals being 5,255.

Vaccinations continue to be at the heart of the Biden administration’s COVID response strategy. 

The White House has already ordered over 170 million doses of the new vaccine for a fall booster campaign, and, now that the FDA has weighed in, expects those boosters to reach the states in a matter of days.

Dan can be reached at [email protected] and at https://twitter.com/DanMcCue.