In the last nine days I’ve done two online debates on variolation, with Zvi Mowshowitz and Gregory Cochran. In both cases my debate partners seemed to basically agree with me; disagreements were minor. Last night Tyler Cowen posted 1000+ words on “Why I do not favor variolation for Covid-19”. Yet oddly he also doesn’t seem to disagree with my main claims that (1) we are likely to need a Plan B for all-too-likely scenario where most of the world seems likely to get infected soon, and (2) variolation is simple, mechanically feasible, and could cut Covid19 Deaths by a factor of 3-30.

Tyler lists 8 points, but really makes 11. If he had one strong argument, he’d have focused on that, and then so could I in my response. Alas, this way I can’t respond except at a similar length; you are warned.

If you recall, for other viruses we’ve seen factors of 3-30 cuts in death rates for low dose infections. This dose effect for viruses is very well established in virology. So I propose to quickly test different ways to dose, deliver, and mitigate Covid19 infections in 1000 volunteers. This is easy, lo-tech, and pretty sure to give big gains. Then I’d open Hero Hotels where one (or one’s health plan) pays to enter, gets quickly deliberately infected, then must stay until recovered, after which one can leave and is certified to work and socialize. This can be completely voluntary, though it could also be subsidized or even required. The young and healthy, and critical workers, seem especially good candidates.

I’ll reply to Tyler’s 11 objections in the order he presents them. First (pt 1a) he says med workers are scarce:

Qualified medical personnel are remarkably scarce right now. I do not see how it is possible to oversee the variolation of more than a small number of individuals.

If variolation cuts death rates by a factor of 5 (median estimate in this poll), it also most likely cuts the rates of needing hospitals and other care by a similar factor. So on average variolation replaces five infected patients needing care over the course of the pandemic with one patient soon. This can be a great trade even at the pandemic peak, and looks even better now, well before the peak.

Tyler says he recalls me making this point, but says “it would take many months for that effect to kick in, or possibly many years.” No, the effect is immediate.

Next (pt 1b) Tyler says that if variolation is voluntary, it can’t help everyone, as some may refuse.

It is possible that many medical personnel would refuse to oversee the practice. The net result would be only a small impact on herd immunity. … The real question right now is what can you do that is scalable? This isn’t it.

But this is a generic argument against any voluntary policy. If it isn’t required, most may refuse, thus producing a smaller effect. There is nothing about variolation that makes it mechanically harder to require than other pandemic policies. But it is worth noting that there is no min scale needed to gain benefits from variolation; every volunteer whose death rate is cut is a gain.

Next (pt 2a) Tyler says there’s no place to put variolation participants:

Where will we put all of the … contagious individuals we create? What network will we use to monitor their behavior? … In essence, we would have to send them home to infect their families (the Lombardy solution) or lock them up in provisional camps. Who feeds and takes care of them in those camps.

This is a Plan B policy, for the scenario where we reluctantly conclude that probably most people will get infected soon. In this case, variolation doesn’t change the total number of people who are ever infected, it just moves some of their infection dates to earlier dates, and also swaps who is infected from random folks to the folks we choose. Variolation also does not change the usual fact that stronger more reliable isolation is more expensive. Yes, isolating people at home can be cheaper but is less reliable, but that is true no matter how people get infected.

However, variolation offers one huge advantage re isolation costs. With accidental infection, one must crudely target isolation resources at those who seem most likely to have been recently infected, and thus contagious. So most isolation is wasted on people who are not actually infectious, and one is tempted to invade privacy to get better weak clues on who might be infected. In contrast, with deliberate infection we can target isolation resources exactly to those who have been recently infected.

As a result, the same amount of isolation resources can produce much lower rates of the infected infecting others, or the same infection rates by the infectious can be produced via much fewer isolation resources. In addition, instead of having to search for people to isolate and then force them into isolation, the prospect of gaining lower death rates can tempt people to voluntarily seek out and accept isolation and its enforcement regime.

Next (pt 2b) Tyler worries about how to keep people in isolation:

Under the coercive approach, what is the exact legal basis for this detention? That a 19-year-old signed a detention contract? … Where are the governmental structures to oversee and coordinate all of this? … Will any private institutions do it without complete governmental cover? I don’t think so. If all this is all voluntary, the version that Robin himself seems to favor, what percentage of individuals will simply leave in the middle of their treatment?

These are issues for any pandemic policy that seeks to promote isolation of the infectious. It isn’t particular to variolation. But variolation makes these easier via making it much easier to identity the infectious, and by getting them to voluntarily agree to isolation measures. Whatever problems Hero Hotels might have with enforcing isolation, surely such problems are much harder when trying to force isolation on random people whom a distant government suspects might be infectious.

Next (pt 3) Tyler says no one wants this:

Note that the purely voluntary version of Robin’s plan can be done right now, but does it seem so popular? Is anyone demanding it, any company wishing it could do it for its workforce? The NBA has an amazing amount of money, on-staff doctors, the ability to afford tests, and so on. And with hundreds of millions or billions of dollars at stake they still won’t restart a crowdless, TV-only season. They could indeed run a “Heroes Hotel” for players who got infected from training and play, and yet they won’t. “Stadium and locker room as Heroes Hotel” is failing the market test. Similarly, colleges and universities … are not rushing … even if it might boost their tuition revenue.

Come on, this stuff is heavily regulated, and this concept generates an “ick” reaction in many! I’ve heard from many who say they personally want variolation, the NBA and colleges are especially risk-averse re median public opinion, and it isn’t clear that any organization has legal permission to do this now. For example, it is now considered quite controversial if to allow “human challenge” studies wherein volunteers are deliberately infected with the virus to test vaccines. Such permission hasn’t yet been given. So clearly our highly regulated regimes of medicine and safety have not yet given a clear regulatory go-ahead to Hero Hotels. Gaining clear legal permission is a big first priority here.

Next (pt 4a) Tyler suggests we’d get the same effect via just letting the young range free:

Does small/marginal amounts of variolation do much good compared to simply a weaker lockdown enforcement for activities that involve the young disproportionately? Just tell the local police not to crack down on those soccer games out in the park.

But letting the young range free doesn’t ensure that their infections are via low doses, and it doesn’t isolate them to prevent their spreading the pandemic to others. How could anyone see this as remotely similar to my proposal? Yes, my guess is that it is better to variolate the young, but variolation is much more than merely trying to get the young infected first!

Next (pt 4b) Tyler repeats his complains above, which I’ve already addressed, that variolation requires “extra” medical or isolation resources.

Robin’s idea has the “Heroes Hotel” attached, but that is a deus ex machina that simply assumes a “free space” (both a literal free space and a legally free space) is available for experimentation, which it is not.

Next (pt 5) Tyler says we just can’t allow people to do things that leaders don’t have time or political cover now to explicitly endorse:

Society can only absorb a small number of very blunt messages from its leaders. You can’t have the President saying “this is terrible and you all must hide” and “we’re going to expose our young” and expect any kind of coherent response. People are already confused enough from mixed messages from leaders such as presidents and governors.

Presidential orders aren’t the only route to helpful behavior! By Tyler’s standard, people should only be allowed to do a few things, as risk-averse political leaders are only willing to explicitly endorse a few activities. If the president hasn’t taken the time and political risk to praise your activity in a speech in the last few years, you may not do it; it is forbidden. That seems just a crazy standard to me. It needs an explicit supporting argument, which Tyler hasn’t given.

Next (pt 6) Tyler warns of non-death damage:

There is still a chance that Covid-19 causes or induces permanent damage, perhaps to the heart and perhaps in the young as well. That does not militate in favor of increasing the number of exposures now, especially since partial protective measures (e.g., antivirals, antibodies) might arise before a vaccine does. This residual risk, even if fairly small, also makes the liability issues harder to solve.

Tyler’s argument here is like warning against seat belts by noting that car accidents cause harms other than death. Variolation is a partial protective measure that reduces damage conditional on infection. I’ve said that it is a Plan B, less appealing if we think we have a high chance of preventing most from getting infected. But assuming most get infected, the more damage that Covid-19 causes, via death or otherwise, the more valuable it is to cut such damage via variolation.

Next (pt 7) Tyler basically repeats his (pt 4a) that variolation is just like letting the young range free.

As lockdown drags on, many individuals deliberately will become less careful, hoping to get their infections over with. A few may even infect themselves on purpose, … [especially] (non-obese) young… That debate will devolve rather rapidly into current discussions of testing, test and trace, self-isolation, antivirals, triage, and so on. And then it will be seen that variolation is not so much of a distinct alternative as right now it seems to be.

Finally, Tyler praises variolation talk for raising issues related to good issues:

The main benefit of variolation proposals is to raise issues about the rates at which people get infected, and the sequencing of who is and indeed should be more likely to get infected first. Those questions deserve much more consideration than they are receiving.

So in summary, Tyler says variolation is bad because no one wants it, it needs medical worker and isolation resources, it is the same as letting the young range free, the virus causes damage other than death, and political leaders won’t take the time or political risk to endorse it. But many would want to cut their death rate by 3-30X if it were legal, variolation greatly economizes on medical worker and isolation resources, it is not at all the same as letting the young range free, more virus damage is more reason to want to cut damage via low doses, and it is crazy to only let people do things that politicians have recently and explicitly endorsed.