background_fid.png
Play Live Radio
Next Up:
0:00
0:00
Available On Air Stations

FDA advisers recommend new COVID vaccines designed specifically to fend off omicron

JUANA SUMMERS, HOST:

A key federal advisory committee today recommended that the Food and Drug Administration tell COVID-19 vaccine-makers to reformulate boosters so they target the omicron variant. The recommendation is aimed at bolstering protection before a possible winter surge of illness. NPR health correspondent Rob Stein joins us now. Hey, Rob.

ROB STEIN, BYLINE: Hey there.

SUMMERS: So the FDA committee says we need new versions of the vaccines designed specifically to fend off omicron. What are they saying, exactly?

STEIN: You know, this could be one of the most important decisions the federal government makes to try to keep the country safe as the virus continues to spread rapidly and evolve. Right now, it may feel like the pandemic is kind of fading into the background, but that could be fleeting. The protection people have had from getting vaccinated or infected continues to wear off, and public health experts are especially worried about another big surge in the coming winter. Here's how Dr. Peter Marks at the FDA set the stage for the daylong meeting today.

(SOUNDBITE OF ARCHIVED RECORDING)

PETER MARKS: That combination of waning immunity combined with the potential emergence of novel variants during a time this winter when we will move inside as a population increases our risk of a major COVID-19 outbreak.

STEIN: So in the end, the committee voted 19-2 that the country should deploy a new generation of vaccines program to target omicron for another round of boosters in the fall. But, you know, it wasn't an easy call.

SUMMERS: Well, just what made it so tricky?

STEIN: Well, you know, there are just so many unknowns. This virus evolves so fast and is so unpredictable that it's really tough to pick the best strategy for a booster campaign, you know, a half a year away. Who knows how much immunity people will have left by then, and who knows what variant will be spreading by then? Here's how Dr. Arnold Monto at the University of Michigan put it. He chairs the committee.

(SOUNDBITE OF ARCHIVED RECORDING)

ARNOLD MONTO: We're being asked, more or less, to have a crystal ball today.

STEIN: And to make things even harder, there just isn't a whole lot of data yet about how much better new vaccines targeting omicron would really be. You know, studies from Moderna and Pfizer and BioNTech indicate that their new omicron vaccines could provide stronger protection than the original vaccines, but it may not be all that much stronger. And those vaccines - they target the original strain of omicron, which has already been replaced by new subvariants that are even better at sneaking around the immune system. In fact, the CDC released new data today that estimates those new subvariants, called BA.4 and BA.5, are now dominant in the U.S., so Pfizer surprised the committee with new data about another new vaccine tailored to fend off BA.4 and BA.5. That looks promising, but that was based on experiments involving mice, so it's even more preliminary.

SUMMERS: So advisors voted to go with some sort of new omicron vaccine. Did they say which one?

STEIN: You know, they didn't specify. But, you know, it was clear that most of the advisers felt that the next booster should target these new subvariants, BA.4 and BA.5. Here's how Dr. Bruce Gellin at the Rockefeller Foundation put it.

(SOUNDBITE OF ARCHIVED RECORDING)

BRUCE GELLIN: In the spirit of the Stanley Cup, where the puck is going rather than where it's been, so I lean to the BA.4 or 5.

STEIN: But many experts endorse targeting both some version of omicron and the original virus to sort of hedge our bets, but it will now be up to the FDA to decide exactly what to do. The agency will probably make its pick by midsummer, and the companies say they could deliver millions of doses of new omicron vaccines by, you know, October or November.

SUMMERS: All right, NPR health correspondent Rob Stein. Thank you.

STEIN: Sure thing.

(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.

Rob Stein is a correspondent and senior editor on NPR's science desk.