Slaoui: We're considering half-doses on Moderna vaccine to speed up vaccinations

The imperative of maximizing the rate of vaccinations has not dissipated in the final hours of 2020. If anything, the question has gotten more acute, even if HHS has managed to accelerate the number of daily vaccinations to 500,000, as Dr. Moncef Slaoui told CBS’ Margaret Brennan on yesterday’s Face the Nation. Even at a half-million a day, it would take almost two years to vaccinate the full American population.

Of course, that could change if supplies increase, Slaoui tells Brennan. After pushing off the idea to use all available vaccines for first doses rather than hold half back for the required second doses for full coverage, Slaoui suggests splitting the baby in an entirely different manner, at least with the Moderna vaccine. HHS and the FDA are considering emergency authorization for half-doses on the first round, which Slaoui insists will provide a similar immune response and could double the number of doses available:

MARGARET BRENNAN: OK, so you’re saying that still has to be up to the states to figure out where they have the need. But let’s talk about the portion you can control, and that is the federal supply. If the goal is preservation of life, how can you still justify holding back more than half of the manufactured doses that you have? You know, we just heard from the UK that they’re just trying to hit as many people at once. Why not do something like that and space out the time between doses?

DR. SLAOUI: Yes, so a scientific answer and then an alternative. I think it’s not reasonable when vaccines have been developed with two doses given 21 days apart, or 28 days given apart, and where we have the data on their safety and their efficacy and we have no- after two doses. We have no data after one dose. If we leave people a month, two months, three months with maybe incomplete immunity, waning immunity, maybe even the wrong kind of immune response induced, that is then corrected by the second dose–

MARGARET BRENNAN: But they’ve got zero immunity right now.

DR. SLAOUI: So give them- well, it is- we- I’m- I’m going to tell you the alternative in one second. Just let me finish the point I’m making, which is we always said that these vaccines will be developed on the basis of science and all decisions will be made transparently on the basis of data. Changing the decisions made, the choices made, which was to give two doses of vaccine, the second dose gives you 10 times higher immune response than the first dose, without any data I think would not be responsible. Here is the alternative. We know that for the Moderna vaccine, giving half of the dose to people between the ages of 18 and 55, two doses, half the dose, which means exactly achieving the objective of immunizing double the number of people with the doses we have. We know it induces identical immune response to the hundred microgram dose and therefore we are in discussion with Moderna and with the FDA. Of course, ultimately it will be an FDA decision to accelerate —


DR. SLAOUI: — injecting half the volume. I think that’s a more responsible approach that would be based on facts and data —


DR. SLAOUI: –to immunize more people. And of course, we continue to produce more vaccine doses.

This seems a bit unclear. Did Moderna actually do a separate Phase 3 trial of its vaccine at half-volume on the first dose and get similar 94% effective results? If so, why didn’t the FDA just approve that regimen (regi-women?) in the first place? And what about the Pfozer vaccine, which is based on the same mRNA technology? They certainly knew that production would be tight at first, so any extra doses that could get squeezed from the initial production runs would be golden.

If this sounds familiar, it should. It recalls the misadventure of AstraZeneca’s Phase 3 trial, in which some of their subjects were accidentally given half-doses on their first round. AstraZeneca claimed that this regimen (naaah) actually worked better than two full doses, but then their record-keeping came into question and they had to extend their Phase 3 trial. If there’s a sound scientific basis for proceeding with half-volume first doses, fine, but if that’s the case then the FDA should have issued its emergency-use authorization on that basis in the first place.

Besides, the problem doesn’t appear to be inventory. The problem appears to be distribution and delivery logistics, problems which this change wouldn’t address in a meaningful manner. By yesterday, we were north of 4 million vaccinations, but we have at least 12 million in inventory at the moment and more coming in. The problem is in getting the existing vaccines into arms at any dose, and it’s leading to some bizarre outcomes. Andrew Cuomo wants to obliterate anyone who gets a dose before their priority gets called, but that means that doses are likely to get spoiled in practice.

If you want to get vaccinated early, my advice is to become bestest buddies with your local pharmacist:

David MacMillan is not a first responder or health care worker. So he was surprised when a pharmacist at Giant Food asked him and his friend if they wanted to get the Moderna vaccine. …

“She turned to us and was like, ‘Hey, I’ve got two doses of the vaccine and I’m going to have to throw them away if I don’t give them to somebody. We close in 10 minutes. Do you want the Moderna vaccine?” he said in the video.

MacMillan didn’t hesitate.

Hey, I wouldn’t have hesitated at that point either. Kudos to Giant and the DC health system for ensuring that such doses will go to use rather than threatening providers and patients with million-dollar fines. The point of producing the vaccine is to vaccinate, not to pose for bureaucratic rules and red tape.

This does, however, point up the folly of attempting to fix a logistics problem by artificially increasing supply. Had Slaoui’s idea been put in place, Giant would have tossed out a lot more than a couple of doses on that night, and potentially left people less well protected on their first dose to boot. The inventory is coming — so let’s fix the logistics of distribution and delivery ahead of it.