FDA panel votes on Pfizer RSV vaccine following efficacy data

Yahoo Finance health care reporter Anjalee Khemlani breaks down what to know about Pfizer's RSV vaccine and the FDA Advisory panel's vote.

Video Transcript

SEANA SMITH: FDA advisors are voting on Pfizer's experimental maternal RSV vaccine. Here with the latest, Yahoo Finance health reporter Anjalee Khemlani. Anj, you've been listening in. You just pulled your earbuds out. What are we hearing?

ANJALEE KHEMLANI: We just got the vote in. So hot off the press, we got a majority of the votes in for Pfizer's maternal RSV vaccine and that's 14 to 0 vote on approving it-- or recommending approval based on the efficacy of the vaccine. But we did get a 10 to 4 vote on voting for on recommendation on the safety profile of the vaccine. I'm going to get to that in just a second.

But just to recap, what we're looking at with Pfizer's vaccine, it is a 120 microgram dose administered to pregnant mothers between the weeks of 24 to 36 weeks. It protects the baby up to six months. That's at least the endpoint that they had notified and it met that endpoint. We noted that in the data, number one, that later in the third trimester is when it seemed to have the best efficacy as well as strongest protection up to 30 days versus after that.

Now, Pfizer is competing with GlaxoSmithKline for RSV vaccines. We did note specifically that GSK actually dropped out or paused their phase III because of certain safety signals, which you can see, of course, indicated in those votes there, specifically on preterm birth. Pfizer noted 5.6% in their vaccine group versus 4.7% in placebo. GlaxoSmithKline noted 6.8% in their vaccine group versus 4.9% in placebo. So the placebo numbers are pretty close.

They also do have some similar indications. One major difference is that GlaxoSmithKline's group also had neonatal deaths reported. So that was a significant safety signal as well and that's what started that pause.

So as it stands right now, Pfizer looks like it's clear for at least a recommendation for a yes vote from the FDA. They are still waiting on the FDA to decide on their older adult vaccine for RSV. They also do have that up for-- waiting for a vote from the FDA.

Meanwhile, GlaxoSmithKline was the first to get the 16 and older RSV vaccine out. So neck and neck really when it comes to it, but Pfizer is the only one on the table right now with a maternal vaccine. So as this moves forward, it'll be the first.

SEANA SMITH: All right, we'll continue to watch out. Anj, thanks so much.