By Josh Nathan-Kazis

The biggest news in U.S. vaccine policy wasn't up for discussion at Thursday's public meeting of the Food and Drug Administration's external vaccine advisory committee.

Two days earlier, FDA Commissioner Dr. Marty Makary and his new top vaccine regulator, Dr. Vinay Prasad, had noisily announced a big change to how the agency approaches Covid-19 boosters. The FDA will still approve new updated shots for seniors and for high-risk adults, the agency leaders said, but will need new randomized, controlled trials to approve new shots for young and healthy adults.

Regulators had already been leaning toward narrowing the rollout of this year's updated Covid-19 vaccine anyway, after recommending the shot for virtually everyone last year.

But the framework the new FDA leaders laid out on Tuesday raised small and big questions about the regulatory process, vaccine access, and medical ethics.

None of those questions were answered at the Thursday meeting -- leaving the impression that the policy and its implications may not yet be fully fleshed out.

Questions from advisory committee members about how the new framework would apply to the decision they were making at that meeting went unanswered. FDA officials were vague and didn't offer details. One committee member raised an ethical concern that, if broadly shared, could stand in the way of the clinical trials the new framework is meant to promote.

The committee meeting seemed to re-emphasize the uncertainty under which the Covid-19 vaccine companies are working, following a dramatic change in FDA leadership. Covid-19 vaccine stocks were largely down Friday, with Novavax and Moderna off 2.7% and 3.5%, respectively. American depositary receipts of Novavax partner Sanofi were down 0.7%, while Pfizer was up slightly.

In comments at the start of the Thursday meeting, Prasad discouraged discussion of the announcement he had made two days earlier.

"Those of you on this committee, you know how to reach me and my team," Prasad said. "But for today, today's meeting, we have a very specific and very important goal."

The FDA had convened its vaccine advisory committee to talk about what strain it should ask manufacturers to design their fall Covid-19 boosters to target. The committee members eventually voted unanimously in favor of a Covid-19 booster that targets JN.1, the same virus family that last year's booster targeted. The FDA said late Thursday that that new Covid-19 shots should target JN.1, and if possible a strain within that family called LP.8.1.

There were basic questions about how the FDA's decision interacted with the new framework, however, that went unanswered at the meeting. When committee members asked if companies would need to run new randomized clinical trials if this year's shots targeted a different family of the virus from last year's, FDA officials didn't respond directly.

"I think that's a little off topic," said Dr. Jerry Weir, a longtime FDA official, when asked that question by one of the advisory committee members, a CDC official named Dr. Sarah Meyer. "He just released this earlier this week," Weir said of the new Covid-19 vaccine framework. "We're still in discussions within the agency, and with manufacturers."

When another committee member, Dr. Stanley Perlman, asked a similar question later in the meeting, another senior FDA vaccine regulator, Dr. David Kaslow, also deflected. "The goal today is to figure out what the selection of the strain is," he said. "Our goal is not to impact the timely availability of vaccines."

The implications of the new framework that Makary and Prasad announced this week for the fall booster aren't at all clear. On its face, it appears that the FDA will only approve a fall booster for adults over the age of 65, and for people at high risk of severe disease. That will leave the Centers for Disease Control and Prevention's ability to play its normal role of recommending how a vaccine should be used limited.

Prasad and Makary noted on Tuesday that a large portion of American adults qualify as high-risk, and would be eligible for an updated shot even if they were under 65. The practicalities, however, are complex. In prior years, getting a shot was as simple as showing up to a retail pharmacy and waving your insurance card. Now, who will decide whether a patient who wants the shot qualifies as high-risk?

Patients who want the shot but don't qualify might be able to pay out of pocket to get the vaccine off-label. Both the Pfizer and Moderna shots cost around $140, according to the CDC. But availability might depend on state law, and could be cumbersome.

In rolling out the new plan, Prasad and Makary presented it as part of a commitment to "gold-standard science." But during the Thursday meeting, one of the committee members suggested that the randomized, controlled trials that the FDA leaders now want drugmakers to conduct in 50 to 64-year-olds may not be ethical.

"I very much appreciate the idea that we do want to know that there is some efficacy," said Dr. Eric Rubin, editor in chief of the New England Journal of Medicine. "But number one, it does appear that there is efficacy...which might mean that a randomized controlled trial has no equipoise right now, and that you cannot do one."

In research science, "equipoise" means that scientists don't know whether one intervention or another works better. It's the ethical prerequisite for running a clinical trial, and Rubin was saying, in effect, that the Covid-19 vaccine works, and that it may not be ethical to run a test where some patients get the Covid-19 shot and some get a placebo.

"I don't think the [randomized, controlled trial] is feasible," he said.

Makary and Prasad obviously disagree. But if top scientists question whether their plan can be put into effect on ethical grounds, it could point to trouble down the road for the new FDA framework.

Write to Josh Nathan-Kazis at josh.nathan-kazis@barrons.com

This content was created by Barron's, which is operated by Dow Jones & Co. Barron's is published independently from Dow Jones Newswires and The Wall Street Journal.

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May 23, 2025 13:16 ET (17:16 GMT)

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