Over the weekend, I received a message from a physician who specializes in infectious disease at the University of Virginia, Dr. Costi Sifri. His analysis of the US Food and Drug Administration’s advisory panel was so interesting that I asked him if I could share it with you (edited for this format) along with some comments.
Costi Sifri: I think the decision was pragmatic to a T, but I don’t think the headlines following the meeting were accurate. The press reported that VRBPAC [the Vaccines and Related Biological Products Advisory Committee] rejected a broad booster recommendation for the Pfizer vaccine for everyone age 16 years of age and older and instead decided to narrowly focus third or booster doses to smaller, high-risk populations. In doing so, VRBPAC was able to demonstrate its independence. Plus they’ll be able to say that they did not extend the boosters to populations, such as those 16-17 years of age, where there was little to no safety data. But the population VRPBAC outlined is actually not at all narrow and includes a huge swath of U.S. adults. We really don’t have data that supports the need for 3rd or booster doses in many of the groups included. So, I feel the committee painted outside the lines of where the data currently stand. One can’t help wonder if the recommendation would have been as broad if it weren’t for the earlier messaging from the White House/Health and Human Services.
Inside Medicine: It’s interesting that Dr. Sifri points out that the outcome was basically a compromise. That’s provocative and insightful. I had viewed the decision as tracking about as closely with “following the science” as we were going to get. But maybe he’s right and this was just a reflection of politics as much as anything else.
CS: Speaking as someone who helped developed a mass vaccination program here at UVA, this really is, in essence, a recommendation for a mass vaccination booster program for most adults in the country based on, as you’ve written, fairly thin data. If you think about it, individuals 65 years of age and older, healthcare workers, and frontline workers encompass a fairly large portion of the US population.
Inside Medicine: Honestly, I had not considered that. I just checked some data around that. There are around 54 million people in the United States ages 65 and older. There are another 16 million healthcare workers.
CS: My recollection with the vaccine rollout last winter was that a lot of people were eligible earlier than most people realize. Once you add in the “at-risk” population who will also now be eligible for boosters, I wouldn’t be surprised if it turns out that Friday’s vote basically implies that 65-70% of the adult US population will soon be eligible. The added groups are absolutely huge and I’m not sure many or most of them really need boosters now.
Inside Medicine: Again, I had not thought to run those numbers and it’s a simple but superb insight. When you add up everyone who conceivably could be included in the "yes to boosters" group, the numbers are striking. Reading that made me a little queasy; suddenly it feels like Dr. Sifri’s assessment is completely correct and that Friday’s vote will essentially open the flood gates to hoards of people who actually do not need boosters, and for whom more data are needed before we can conclude that boosters are both safe and effective to those populations.
CS: Personally, I don’t oppose protecting highest risk individuals and I liked the original FDA exploration with ACIP, which was nursing home residents, the elderly, and people ages 65 and over. But frontline essential workers were added out of concern for high-risk exposure to the public, a rationale similar to boosting healthcare professionals. But many of those exposures may not be all that similar to exposures in medical settings in terms of the risk posed to the public. Furthermore, healthcare worker exposures and breakthrough infections originate from household contacts and community contacts, not exposures from clinical care.
Inside Medicine: I’m not entirely convinced of that last point to be honest, to be honest. I think PPE and vaccines have limited spread in healthcare settings, but we’ve seen data suggesting that healthcare workers do in fact spread this virus, despite our best efforts. Delta may end up being even more difficult to control. That said, a lot of spread in these settings originates from unvaccinated individuals, and less from breakthrough cases among vaccinated care providers.
CS: Also, including high-risk individuals in the booster group makes some sense, but could cause problems too. I anticipate that what qualifies as a pre-existing condition will be viewed/interpreted with the same loose honor code system as the three dose vaccines for the immunocompromised have been since August [i.e. not very rigorously]. So I think Friday’s vote implies a much larger segment of the population than most people realize will now be eligible for boosters, and the data presented regarding reduced effectiveness and safety in younger people were quite thin.
Inside Medicine: Such an excellent point. That said, I think most people, myself included, saw the result of Friday’s vote (and the tone of the deliberations) and correctly concluded that the data are just not yet there to support boosters for young and healthy people with no unusual personal risks to consider. Sure, many “booster boosters” may be able to sneak in a 3rd shot on some technicality, but I think most people will have interpreted Friday’s vote as a sign that the case is not closed and therefore will in fact wait for more safety data before proceeding.
Did the FDA panel’s decision surprise you? Did it change your personal willingness to line up for a booster in one direction or the other?