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“A better way to roll out Covid-19 vaccines: Vaccinate everyone in several hot zones”?

Peter Dorman writes:

This [by Daniel Teres and Martin Strossberg] is an interesting proposal, no? Since vaccines are being rushed out the door with limited testing, there’s a stronger than usual case for adaptive management: implementing in a way that maximizes learning. I [Dorman] suspect there would also be large economies in distribution if localities were the units of sequencing rather than individuals. It would be useful to hear from your readers what they think a good distribution-cum-research-design plan would look like.

In the article, Teres and Strossberg write:

Vaccines are on the brink of crossing the finish line of approval, but the confusion surrounding the presidential transition has brought great uncertainty to the distribution plan.

The National Academies of Sciences, Engineering, and Medicine developed an ethical framework for equitable distribution of Covid-19 vaccines, as have others. But national plans based on these frameworks are problematic. They recommend giving the vaccine first to Phase 1a front line high-risk health workers and first responders. That stretches the supply chain to include workers in every hospital, nursing home, long-term care facility, as well as all ambulance, fire rescue, and police first responders. . . .

We propose a different approach: target several hot zones with high numbers of Covid-19 cases, especially those zones with rising Covid-19 hospitalization rates. . . . Vaccination within each hot zone would begin with Phase 1a individuals and then move on quickly through Phases 1b, 2, 3, and 4. . . .

We believe that our approach offers the best way to break the chain of transmission. The first 60 days will be key in showing the results. Our plan has many advantages over the “phase” plan proposed by the National Academies.

This seems reasonable to me. On the other hand, I don’t know anything about this, and I’m easily persuaded. What do youall think?


  1. John Williams says:

    Whether the Teres and Strossberg proposal makes medical sense or not, politically it is a non-starter. How do you persuade politicians in the majority of districts that are well down the list that their most vulnerable constituents should wait while healthy young people in other districts get vaccinated?

  2. I wonder whether those that have had COVID19 are being encouraged or discouraged to get vaccinated. What is their status in the scheme of things? As I have mention before we don’t really know the true denominator of those that caught the virus.

  3. Joshua says:

    Seems the efficacy of such an approach would be partially a function of the political and ideological characteristics of the area. I assume vaccination rates might vary considerably across the country/globe.

    Unless you’re talking about forced vaccination, and that ain’t gonna happen.

  4. Steve says:

    I think proposal has a lot of merit. If we had an HIV vaccine, we would give it to sex workers first. If we could identify the super-spreaders for COVID, we should give it to them first. But, I think that is politically impossible. It will look like rewarding those whose behavior made the pandemic worse.

    Also, this proposal would be a logistical nightmare. If you want to distribute in a hot zone, while the availability of the vaccine is limited, you need to make sure that you aren’t vaccinating the already infected. That means you need to test and get results back quickly. The PCR tests in my neighborhood are still taking days to get back. The rapid tests have a higher error rate. There is a big risk in vaccinating people who are already sick and then having the public loss confidence in the vaccine. Peter’s proposal is a good idea that could work if someone spent the last year planning carefully how to implement it and sell it to the public. But that’s not happening.

  5. Fred says:

    I believe a lot of people are being a little too alarmist about the proportion of Americans unwilling to get vaccinated.
    Having said that, I just do not see how ‘there are several vaccine options, but we are assigning one for your county and you are stuck with it because we want to maximize the speed of learning about the side effects’ is going to play well with the public.

  6. Nedson says:

    This sounds like a proper idea! It would be the best way to move forward vs this pandemic!

  7. Peter Dorman says:

    Yes, the drawback with any serious application of the adaptive management idea is that you’re constraining policy implementation in some way in order to acquire more information. (The adaptive part, for those not familiar with the theory, is that in a lot of management situations there are big gaps in your knowledge, or the situation keeps changing, and so resources and implementation degrees of freedom should be devoted to increasing your learning so you can continue to adjust/adapt the policy as you go along.) That usually means some immediate loss of effectiveness or some other good thing; research gains rarely arise as a free lunch.

    I had the experience many years ago of being a consultant for a state-level agency that wanted to test the rollout of a new policy. Of course, I proposed a (partially) randomized treatment-control framework and developed implementation options to operationalize it. But the political people on top would have none of that. They were aghast that *any* steps would be taken that would slow the pace of implementation or channel it away from their own priorities, so all that work went nowhere. I guess I was the one who had the “learning” in this case.

    RCT’s sometimes have this problem, but it is limited when the treatment is additional — when it would not have occurred at any scale without the advent (and funding) of the randomista investigators. Full blown adaptive management is trickier because it typically constrains an implementation that was already expected to take place.

    So with the vaccine rollout, I can see why there would be pushback. Real lives are at stake, and the values underlying prioritization schemes matter a lot to people. On the other hand, one should also look concretely, so far as that’s possible, at what might be gained from a learning-centered distribution. In particular, we might get a much faster and better understanding of the transmission effects of these vaccines and how they vary by formulation, exposure density, demographics, etc. How much is that worth?

    • John Williams says:

      Adaptive management was first proposed for managing fishing effort on salmon populations, in a situation where fish were harvested as they returned to streams to spawn. The idea was to clarify the number of spawners that would maximize the number of surviving progeny (density-dependent mortality makes this non-trivial), and the question could be addressed by managing harvest and counting spawners. The idea has been popular in resource management, but hard to implement.

      As Dorman says, adaptive management is about making learning an objective of management, but you have to be clean about what you want to learn. Now that I’ve read Teres and Strosberg’s article, I’m unclear just what they want to learn, and why their approach would be the best way to learn it. For example, the first point they mention is learning whether the vaccination program would break the chain of transmission. If the vaccine prevents clinical disease, then how would vaccination not break the chain of transmission, unless vaccinated people could nevertheless be infectious. Why not address that question by sticking swabs up their noses and doing PCR tests? And, if people in the trial were being tested regularly, which seems likely since asymptomatic disease is common, wouldn’t you have a pretty good idea of the answer already?

      As a second problem, the experimental design seems to ignore travel. I live in a county that has had lower prevalence of Covid than most of the state, and the Covid infections here have been driven mostly by people traveling to other areas and bringing it back with them.

      • dhogaza says:

        “If the vaccine prevents clinical disease, then how would vaccination not break the chain of transmission, unless vaccinated people could nevertheless be infectious.”

        For starters, about 6% develop the disease and therefore are infectious.

        One of the lead scientists at Pfizer says they’re expecting the vaccine to be at least 50% effective at reducing transmission. Given how mild the cases were of those who got the disease despite vaccination, they’re obviously hopeful it will be far more effective than that, but just how effective is totally unknown at this point.

        If you want a classic example of how vaccination may not break the chain of transmission, read up on the pros-and-cons of the injected vs. oral polio vaccines. The specifics don’t apply here, but does demonstrate that the assumption that if a vaccine prevents disease it also prevents people from becoming infectious.

        • dhogaza says:

          “The specifics don’t apply here, but does demonstrate that the assumption that if a vaccine prevents disease it also prevents people from becoming infectious” …

          doesn’t always hold

        • John Williams says:

          Agreed that vaccination may not break the chain of transmission, but my point is that there are easier ways to test the whether vaccinated people are still infectious.

  8. Mendel says:

    I doubt the “economies in distribution” for county-level deployment exist: while a county may have the resources to store and administer vaccines for its front-line care workers, no county has the resources to do it to their whole population; and creating or importing this infrastructure from scratch has to be more expensive than reusing existing infrastructure.

    If you can get care home personnel inoculated, you’re going to have a leverage effect in that this will also protect the care home residents better even if they’re not getting vaccinated (yet). This will have an immediate effect on the death toll.

    Vaccinating on a county basis sets up incentives for counties to behave recklessly: policy makers could reason that behaving recklessly gets them relief faster so that they can open up for good more quickly. I don’t think that is a good moral signal to send, and it could make the overall situation much worse.

    • Peter Dorman says:

      Agreed that the rebound effect is a concern. It would be useful to have a rough empirical measure of its magnitude across different populations. That could inform campaigns to counter it. Incidentally, rebound will be a serious problem no matter how the vaccines are rolled out. (This was also an issue when ART’s were first rolled out against HIV/AIDS.)

      What’s a good framework for measuring rebound and also measuring the effect it has in a community that is gradually getting vaccinated?

  9. Psyskeptic says:

    We need to be careful of the incentives here.

  10. Graham says:

    In the US, everywhere is a “hot zone” except Hawaii

  11. Michael J says:

    I agree with other commentators that in a vacuum this may be a good idea but once you factor in politics, public opinion, and moral hazard it may not be. It may seem very unfair to the public that places doing the worse, possibly because lack of good governance, would get rewarded by being first in line. And as Mendel says above, this creates a bad incentive problem. Maybe a lottery could help with this? There are certainly many areas in need right now so the value lost from vaccinating the 100th worse place compared to the 10th worse place may not be large. You would also need to stratify by urban/rural for fairness purposes, even though I’m guessing urban places have better infrastructure to distribute a vaccine, especially given the cold chain requirements.

  12. John Williams says:

    The AstraZeneca trial is now published (, so we have to consider the likelihood that there will be different vaccines with different attributes available. The AstraZeneca vaccine seems to be less effective than the others, and was tested on younger people, but it has major logistical advantages. So, if we are thinking of the vaccine delivery as an experiment, how does that factor into the experimental design?

  13. BB says:

    The reason this seems like a bad idea to me (on the face of it) is that I am under the impression the logistics take a bit of time to plan out.

    For example, imagine Arizona is giving out 150k vaccines a week but then is declared a “hot zone”. Now, they get 500k vaccines a week which is subject to either stay at 400k if they continue being a “hot zone” or go back to 150k a week if the data goes the other way. Suddenly, they have to figure out how to triple their vaccination administering capacity. Do they have to hire more help? Do they open these new doses to first come firs serve or do they have to hire more people to do the administering for who is next in line? Presumably nurses would be busy if hospitals are full. If they are lucky enough to staff up properly in one week and reserve bigger spaces – will they even be in the “hot zone” still?

    I’m skeptical that a more clear plan where states are given an exact description of how many doses they will receive every week would lead to better planning.

  14. Peter Dorman says:

    As I’ve thought about this some more, it seems to me that the most important learning objective is probably how infectious people are after they’ve been vaccinated compared to before. I don’t have the background to know if this can be determined quickly through lab methods, but if not, an experimental roll-out would be a plausible alternative. Vaccinate different proportions of selected communities, like 30%, 50%, 70%, etc., taking into account refusals; that is, offer to vaccinate until the target proportion is attained. Employ the same risk communication strategies on the treatment communities used elsewhere: explain why masking and distancing are still crucial, etc. (GPS or other monitoring can be employed to estimate the degree of behavioral change, although that may not be important, since what we want to know is community case rate trajectory in real life with all the behavioral factors folded in.)

    Yes, travel confounds the purity of the experimental design, but (a) that can be monitored and (b) what we want to know are actual and not hypothetical or pristine community level effects.

    Of course, the politics of getting buy in for such an approach would be difficult, to say the least. Maybe not possible.

  15. Carlos Ungil says:

    Maybe I misunderstood the proposal but vaccinating say North Dakota residents before New York residents could be perceived as punishing the latter for their good behavior and condemning them to more months of containment measures.

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