Gottlieb is a member of Pfizer’s board of directors so you’re welcome to discount his arguments in favor of booster shots if you like. But he’s only saying here what Fauci and eminent immunologists like Stanley Plotkin have said elsewhere lately. It’s not unusual for people to need three doses of a vaccine rather than two in order to build durable immune memory against a particular virus. And there was no way to know up front how many doses it would take of a novel vaccine like the mRNA platform to instill durable protection from a novel virus like SARS-CoV-2.

Although I don’t recall many, or really any, warnings from Fauci, Gottlieb, and the rest earlier this year that three doses was a strong possibility. All I remember is being told that the vaccines do a nearly miraculous job of preventing severe illness from COVID, which was true, and that those of us who’d gotten our jabs could unmask and get back to normal. And then Delta arrived.

If three doses rather than two are needed to elicit robust, mature immunity, should we assume that we’d still be seeing a wave (albeit a lesser wave) this summer if Delta had never emerged and Alpha was still the dominant variant? If not, if our current situation is more of a “Delta problem” than a “COVID problem,” then why should we assume that our immunity after two doses is still “immature”? Maybe it’s mature but Delta is just better at punching through it.

Here’s Gottlieb saying that if you’ve had your two shots then effectively you may have had only one shot. Which would mean virtually every American who thought they were fully vaccinated is only partially vaccinated as we head into Delta’s turbo-charged winter-wave season. Watch, then read on:

"The first two doses were provided so close together that they probably really served as two primes…This third dose is probably going to serve as a true booster in terms of inducing immune memory and…a more durable response," says @ScottGottliebMD on Covid-19 booster shots. pic.twitter.com/1SPjzMKiT1

— CNBC's Closing Bell (@CNBCClosingBell) September 3, 2021

There’s circumstantial evidence that Gottlieb is right. I’ve written before about how studies from the UK show a much stronger immune response when there’s a delay of several months between the first two doses rather than several weeks, as Pfizer and Moderna recommended. Giving the immune system more time to “mature” after its first exposure to the spike protein may produce more durable immunity. Dr. Marty Makary, who’s a frequent guest on Fox, delayed his own second dose by three months expecting that he’d get more of a boost from it. He’s now urging public health officials in the U.S. to consider a longer delay between the first and second shot to give other newly vaccinated people the same boost:

Hematologist Paul Moss, MBBS, PhD, a co-author of the study, concluded that it’s a good idea to extend the time between the first and second doses of the vaccine. “An extended interval may help to sustain immunity against COVID-19 over the longer term and further improve the clinical efficacy of this powerful vaccine platform,” he wrote…

The U.S. basis for designing the 2-dose regimen with a short interval was that the pandemic was raging and there was an urgency to getting the trial done quickly. It was also believed that a short interval could more rapidly address a spike in cases. Based on the thinking at the time, the short interval may have made sense. But some vaccinologists have pointed out that the two doses were so close together that they functioned as a single primer dose.

Note the last sentence, which echoes Gottlieb’s point precisely. It may be that durable immunity against COVID requires a particular duration of time between doses, not a particular number of doses. Two shots might do it if those shots are sufficiently spaced out. Makary suspects he’ll never need a true booster shot because of his three-month delay. But for the rest of us who followed the recommended three- or four-week regimen, our immunity against COVID may remain “immature” to some degree until we get our third dose.

Which makes it … problematic that the feds are suddenly talking about slow-walking approval for the booster shots, not knowing if they’re “needed” at a moment when the vaccines are still providing strong protection from severe illness.

I don’t understand that logic, and I don’t understand how the feds don’t understand how the vaccinated are likely to react once the message penetrates from Fauci and Gottlieb that they’re not truly “fully vaccinated” yet. Here’s a middle-aged former world-class athlete, seemingly otherwise in good health, tweeting from a hospital bed because his encounter with Delta knocked him out despite the fact that he got his two shots:

Wanted you to hear directly from me that despite being fully vaccinated, I have contracted Covid and am not going to be able to fight next weekend. Preparing for this comeback has been everything to me over the last months, & I want to thank everyone for their tremendous support. pic.twitter.com/0wKEnr5Jzv

— Oscar De La Hoya (@OscarDeLaHoya) September 3, 2021

De La Hoya is an outlier, as two doses are enough to keep most people out of the hospital. But between the ferocious wave that Israel experienced this summer, the studies showing that the vaccinated can carry the same viral load as the unvaccinated, and anecdotal reports like the clip above of immunized people having a rough time with the virus, the vaccinated are going to be highly motivated to get that third shot. They’re risk-averse by nature. And right now Fauci and Gottlieb are telling them they haven’t hedged their risk properly yet.

Some doctors seem to believe that as long as the vaccines continue to hold up against severe illness, the case for boosters is weak. I don’t understand that logic either:

In a geographically small area like Israel with 9.1 million people, hospital capacity is everything. If hospitals in Louisiana are full, doctors can send patients over the border to a hospital in a neighboring state if that becomes absolutely necessary. You can’t exactly do that in Israel. So, a booster rollout that essentially “flattens the curve” could have important implications in one country, but negligible ones in another. The reality is that if boosting merely flattens the curve for a few weeks or a few months, little would have been achieved in areas with enough capacity to treat all Covid-19 patients. But there could be harms, not to mention that a systemic booster campaign is all but sure to widen vaccine disparities both here and overseas.

Given that so far all signals point towards the fact that the two-dose coronavirus mRNA vaccine regimens have the same ability to keep infected patients out of the hospital as the three-dose Pfizer regimen, we need to remind ourselves of why we vaccinated in the first place: not to end infections (though that would be nice), but to eliminate most of the horrifying implications of those infections, such as critical illness and death. We’ve achieved that.

It would be lovely if the solution to crowded hospitals in the U.S. were as simple as moving critically ill patients to less congested health systems. But in some cases lately there haven’t been any less congested systems nearby.

As for ending infections, it would be more than “nice” to limit those before the winter wave begins gathering. Fewer infections means less transmission and less transmission means fewer deaths and much, much less human misery. Not just human misery in the form of a bad case of COVID either, since many vaccinated people will be less likely to socialize normally until they’ve had a third dose to fully hedge their risk. Some vaccinated parents may fear they’ll infect their unvaccinated children until they’ve gotten a booster. The belief that the only risk worth considering in deciding whether to give third doses is the risk of hospitalization for COVID is short-sighted, but typical of public health experts. There are all sorts of intangible benefits from letting risk-averse people reduce their risk. And tangible ones too, of course, in the form of increased economic activity.

Even if a third shot doesn’t do anything to increase the durability of a vaccinated person’s immune memory and instead “only” increases their antibodies against the virus for, say, six months, that alone justifies the booster, no? More antibodies in the average person should lead to fewer infections and shorter illnesses amid the winter surge. And probably save a few lives as well.

I think there are only three questions relevant to the booster calculation;

1. Does the third shot do anything meaningful? Reducing the risk of infection and mild illness ahead of a seasonal wave counts as “meaningful.”

2. Does the third shot generate side effects severe enough that we might plausibly say it does more harm than good?

3. Would providing third shots meaningfully deplete our ability to vaccinate the world or are we ramping up manufacturing to serve that end?

I’ll leave you with Leana Wen making the case that we should let the vaccinated get boosters if they like and then track their outcomes, side effects, and so on. There’s no reason America should have to rely on Israel for all of its vaccine data.

The public health focus should be on getting initial doses to those who have yet to be vaccinated. However, we also need to acknowledge that over a million Americans have already received unauthorized third doses. Let’s collect data on them instead of forbidding this practice. pic.twitter.com/LX4Y2Q3v1M

— Leana Wen, M.D. (@DrLeanaWen) September 4, 2021