FDA advisory committee jettisons universal boosters.

Friday, an advisory committee on vaccines for the US Food and Drug Administration voted down Pfizer’s proposal for Covid-19 vaccine boosters for everyone 16 years or older who are more than 6 months out from completing their initial vaccination series. Boosters for those ages 65 and older passed. Frontline workers and other people at high risk for severe disease were also supported. Based on these votes, the FDA will make a final decision soon.

I was actually being interviewed by ABC Nightly News when the news broke that the panel had voted against boosting everyone over 16. It wasn’t a live interview but the reporter read me the result and asked me for my immediate, honest, gut reaction. Naturally, I did what anyone being filmed on national television would do in the face of such new information without adequate time to process it: I absolutely did not supply him with my immediate, honest, gut reaction! I said something vanilla. (They ended up using one decent quotation from me, which is always appreciated).

The truth is that my immediate, honest, gut reaction—my personal Inside Medicine if you will—was somewhere on the surprise-satisfaction-joy spectrum. I genuinely had not realized until right then that even though I felt the data only supported boosting people over 60 years old (and the evidence even for that remains a little thin for my taste), I half expected the panel to bow to pressure and support boosters for everyone, as Pfizer requested. (My on-the-record prediction had been that they would only approve boosters for older people, but I guess I was more pessimistic that they’d get it wrong than I realized).

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Why did I think that the committee would green light boosters for all? Because I had read the briefing document that Pfizer had submitted to the FDA ahead of Friday’s meeting. The document was a muddled mess. One sentence referred to infections, the next to symptomatic disease. It was a lot of bobbing and weaving on whether Delta or waning immunity was to blame for breakthrough infections, all the while boasting about how successful vaccines have been. The prevailing sense I had reading the file was intellectual whiplash. I was worried that the panel, would basically buy into it because the document was, in effect, an information firehose (Pfizerhose?) approach. I think Pfizer hoped that if they drenched the committee with droves of data, nobody would be able to process and reconcile it all and they’d just rubber stamp it.

In my view, though the biggest weakness, was that the document included safety data for 306 boosted individuals ages 16-55. That’s it. 306. We know that the rates of serious adverse events are far more unusual than 1 in 306, even for the highest risk demographics (younger males). That means that unless a disaster of biblical proportions were to occur, no major problems were likely to be detected. In fact, the rate of serious side effects in most if not all age groups included is likely to be more than 20 times lower than 1 in 306. You would need to follow many thousands of test subjects, possibly tens of thousands, before you could make any reliable safety assessment. It bears mentioning that Pfizer could easily enroll that many test subjects in a booster study. My Twitter feed alone seems to be clamoring with booster boosters who seem to have forgotten that risk-benefit analyses do in fact include risks. I’m sure Pfizer would have no problem finding thousands of young and middle-aged adults to volunteer for a booster study. And indeed, that would be helpful information because we would quickly and decisively learn whether boosters had any favorable impact, or any harm.

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Finally, today’s vote may actually have a paradoxical effect in the end. By voting “no” on universal boosters based on the data we have now, the committee might have initiated a journey ending with more young people accepting boosters down the road. If the FDA’s panel had voted in favor of universal boosters, I believe many young people would have questioned the safety of that approach, given the angst and attention this matter has received (I give the media credit for covering this issue carefully the past month). That also means that if and when data demonstrate that boosters are safe and beneficial for younger demographics, more people will have confidence that the process that led to that decision was a rigorous and minimally political one.

By saying “no” to universal boosters today, the FDA’s committee may have set the stage for more people saying “yes” to them in the future, if and when we all need them.

Later, I’ll publish a series of insights from an infectious diseases doctor on this topic.

Did the FDA’s committee make the right call? Leave your comments below.