This past week saw a bit of infighting at the FDA spilling over into the public. Two respected and seasoned staffers at CBER announced their resignation, apparently fueled by disagreements with White House statements about booster plans, and then they signed on to a Lancet article opposing booster approval. This was in advance of the FDA/VRBPAC meeting on September 17. I urge public officials on all sides to tone down their emotions and just get back to evaluating the evidence.
Mask Slackers
I'm always interested in the history of medicine and thus delighted to see this quick graphic article in the NEJM posted on September 18. The article is free without subscription, take a few minutes to look at it!
The Boosting Evidence
I was able to attend a good deal of the FDA/VRBPAC meeting, including the important discussions surrounding a vote about whether to approve boosters for all individuals age 16 years and above. The event showed some evidence of the earlier drama in the week but mostly was under control. I was very interested to hear discussion of data from Israel and I was in stats nerd heaven with the very cogent discussion of pitfalls in interpretation of "real-world" data. As you probably know by now, the advisory group voted 14-2 against approving the vaccine for everyone > 16 years of age, and in the ensuing discussions what emerged was a unanimous recommendation for authorization of boosters for individuals > 65 plus front line providers and others at high occupational risk like teachers. I think the committee made the right move for now.
Here are 3 takeaways from the meeting, some of which I don't think made it through clearly in the lay press. First, the data presented didn't have long enough follow up information to know whether boosters truly served to dampen the surge curve and significantly lessen morbidity and mortality in Israel. Similar data are lacking for what the US curve is doing now and whether the surge will decrease without immediate boosters. It will be only a few weeks until that information is available. Second, although the Pfizer data clearly show a robust "boost" to antibody in booster recipients, it's based on a small number (around 300) of individuals with limited follow-up. Historically, that number of study subjects is at the low end for what FDA has approved in the past for vaccine boosters, Japanese encephalitis vaccine being an example for that low number. Other booster approvals tend to have involved closer to 1000 subjects.
The third takeaway involves the important concern of safety. In particular, why expose young people to the possible myocarditis risk with a booster dose if the benefits to them and society are a bit fuzzy at present? I did learn that the best estimates for highest mRNA vaccine-associated myo/pericarditis is in 16-17 year olds at about 1 in 5000-6000 recipients. The rate goes down sharply with advancing age. This complication seems very mild at present, but we're still awaiting long-term follow-up of this potential side effect. I am less concerned about this factor than I am about the lack of high-quality evidence that boosters are highly beneficial this soon after primary series.
For those interested, I'll be discussing the booster considerations along with a general COVID-19 update and information about studies in younger children at a Children's National Hospital Pediatric Health Network Town Hall meeting at 12:15 PM EST on Tuesday, September 21. Organizers have told me you don't need to be a PHN member to attend the meeting. As I write this the morning of September 19, we await word from FDA as to official authorization of boosters and then the ensuing deliberations from the ACIP on more specific recommendations. Those meetings currently are scheduled for September 21 and 22.