Posted: January 22, 2021
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Article SummaryA mostly thoughtful debate is raging among vaccine experts on the pros and cons of prioritizing first doses of the two-dose Pfizer and Moderna COVID-19 vaccines, versus the current policy of trying to make sure every first dose recipient gets her second dose on schedule, even though that means more people must wait longer without any vaccine protection at all. I’m not entitled to an opinion on this question. But I hate to see experts and officials on television day after day sounding like they’re on both sides at the same time: ”We need to get as many people as possible vaccinated as quickly as possible" and “we need to make sure people get their second doses on schedule” – as if the same dose could go into two different arms. This short column is a plea to stop asking people to believe that impossible mixed message.

One-Dose Two-Dose Vaccine Risk Communication: Another Impossible Thing to Believe Before Breakfast

Lewis Carroll’s White Queen told Alice she could believe “six impossible things before breakfast.” But asking the U.S. public to believe yet another impossible thing about COVID-19 is profoundly unwise. We have had too many pandemic mistrust debacles already. We don’t need another, this one about vaccine doses.

Yet many experts and officials have been sending impossible mixed messages about second doses. The same mixed messages are coming from Democrats and Republicans alike; I almost entitled this column “One Dose Two Dose Red Dose Blue Dose.”

Message One: In the face of soaring death rates and emerging variants that are thought to be even more transmissible, we must do everything we can to get as many people as possible vaccinated as quickly as possible, starting with the most vulnerable.

Message Two: Everyone should and will get their second dose on schedule, either three weeks (Pfizer) or four weeks (Moderna) after their first dose.

Believing both messages requires believing the impossible. Every vaccine dose that’s in U.S. government hands should go into somebody’s arm as quickly as possible. No debate there. The question is whose arm: somebody who desperately wants an appointment for her first dose, or somebody who already has an appointment for his second?

I’m not qualified to judge which arm should be prioritized. There are pros and cons either way. To oversimplify: Would we be better off a few months from now if all of us were “half” protected or if half of us were “fully” protected? Tough call. We don’t know how long one-dose immunity will last. We don’t know whether the existence of millions of partly immune vaccinees will nurture the emergence of a vaccine-resistant virus variant. On the other hand, we have solid reasons to worry that a terrifying fraction of completely unprotected Americans could succumb to the more transmissible variants we’re already facing.

If single doses stay effective and if they don’t contribute to the rise of vaccine-resistant variants, then the so-called “first dose first” strategy adopted by the United Kingdom is pretty obviously the way to go in the U.S. as well. That’s especially true if the vaccines reduce transmission as well as illness, and if they do so even with just one dose. But what if single doses work for only a month or two, and we end up with a new virus variant that isn’t stopped by the vaccines we’ve got?

There are other unknowns that make this an even more complicated dilemma. Some of them aren’t about the vaccine or the virus, but about the public. Will people’s willingness to get vaccinated, already lower than we wish, decline even further if the government abandons the vaccination protocol that was tested in the Phase 3 trials for a protocol that’s basically untested? Will experts and officials who swore two doses were essential lose their remaining credibility if they reverse course on this issue the way they did on masks? Will people who are told their second dose is being postponed till the indefinite future show up for it when the time comes?

Maybe we should keep giving first doses until there’s nobody left who wants one, and only then cycle back to give them all second doses. That means a much longer wait for second doses than the three or four weeks tested in the Phase 3 trials.

Or maybe we should keep giving second doses on schedule. That means a much longer wait before everyone who wants a first dose gets a first dose.

Or maybe we should compromise by slotting second doses throughout the prioritization categories. For example, we could put second doses for people 65+ after first doses for frontline workers but before first doses for everybody else. We could put second doses for frontline workers after first doses for people with comorbidities but before first doses for everybody else. Etc…. As we’ve all learned, overly complicated prioritization schemes lead to inefficiency, confusion, frustration, and wasted doses. Even so, your second dose is a lower priority than your first dose, so it might be a lower priority than somebody else’s first dose too.

The one thing we can’t do: Put the same dose into two different arms. That’s what we seem to be promising to do.

I have framed this dilemma in terms of doses: With a limited number of doses available, and a limited number scheduled to become available in the months ahead, whose arms should we prioritize? But it’s the same dilemma if the limited resource is something other than doses – whether it’s syringes or vaccinators or appointment slots. Whatever is in the shortest supply, that’s what we need to allocate, either to someone who’s waiting for his second dose or to someone who still hasn’t had her first.

Any expert or official who says “we need to get first doses into as many arms as possible as quickly as possible” is saying we must make every available dose a first dose until there’s nobody left in line for a first dose. You can’t say that and mean it … and still keep scheduling people for second doses.

I’m not referring here to the recent kerfuffle over whether second doses were being held back or not. For a while the Trump administration earmarked second doses and kept them in Operation Warp Speed freezers. Then it decided it could rely on the manufacturers to keep producing doses on schedule. So it started sending the states all the vaccine it had on hand, intending and hoping the supply going forward would continue to be enough for both first and second doses. This policy change was announced as if it was forthcoming, but in fact it had already been implemented, leading some states to expect a bolus of previously withheld doses that never materialized. When Biden announced that he (too) was planning not to withhold any second doses, the announcement led some commentators to think Biden was moving toward a first dose first policy like the U.K.’s.

Not so far. Like the Trump administration, the Biden administration isn’t earmarking second doses and holding them back. But it still intends for every first dose recipient to get her second doses on schedule – while at the same time emphasizing how important it is to vaccinate as many people as possible as quickly as possible. On the one-dose two-dose dilemma, Biden’s pandemic managers are guilty of the same double message as Trump’s pandemic managers.

There’s an ethical and perhaps a legal issue about people who have already been scheduled for second doses, whose first-dose informed consent forms said it was important that they get their second doses on schedule. Are we entitled to break this implied promise if we decide somebody else’s first dose is a higher public health priority?

But most people haven’t had their first doses yet. What implied promise do we want to make to them about second doses?

I don’t know which is the better public health strategy for COVID-19 vaccination right now: one dose or two doses. I’m a risk communication expert, not a vaccine expert. But this I know for sure: One consistent message is better than two conflicting messages – all the more so when trust is fragile and desperately needed.

That’s true even if the one consistent message is a message of uncertainty: “We are undecided about the difficult choice of whether to prioritize first doses over second doses so more people can get at least some protection as quickly as possible, or to continue the current policy of trying to make certain people get their second doses on schedule so they are fully vaccinated.” Sure, nobody likes it when the authorities are undecided, especially in a public health crisis. But candidly undecided is better than bewilderingly inconsistent.

Let’s stop giving the public yet another impossible thing to believe about COVID-19 before breakfast.

Copyright © 2021 by Peter M. Sandman


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