Monday, December 28, 2020

New Paper on Pandemic Ethics

'The Ethics of Deliberate Exposure to SARS-CoV-2 to Induce Immunity', forthcoming in the Journal of Applied Philosophy, by Robert Streiffer, David Killoren, and myself.

Abstract:
We explore the ethics of deliberately exposing consenting adults to SARS-CoV-2 to induce immunity to the virus (“DEI” for short). We explain what a responsible DEI program might look like. We explore a consequentialist argument for DEI according to which DEI is a viable harm-reduction strategy. Then we consider a non-consequentialist argument for DEI that draws on the moral significance of consent. Additionally, we consider arguments for the view that DEI is unethical on the grounds that, given that large-scale DEI would be highly likely to result in some severe illnesses and deaths, DEI amounts to a form of killing. Our thesis is that incorporating a DEI program alongside the status-quo “calibrate-the-curve” responses could have significant advantages at the early stages of pandemics. These potential advantages mean that, at a minimum, research into DEI would have been justified early in the COVID-19 pandemic, and that DEI programs should be explored as potential additions to our overall approach to emerging pandemics in the future.

Quick summary of the harm-reduction potential of DEI:
* We know from other viruses, including SARS-CoV-1, that initial viral load can significantly affect symptom severity.  So we've good reason to expect that low-dose exposures to SARS-CoV-2 would be significantly less harmful than random infections (reducing mortality risk by 3 times or more). Testing this should have been a top priority at the very start of the pandemic.

* Risks could be further reduced by preceding with an experimental vaccine, or providing early anti-viral treatment (which otherwise wouldn't be possible until symptomatic, by which time anti-viral treatment is less effective).
 
* With deliberate infection, you know when to quarantine / self-isolate, greatly reducing the accidental, uncontrolled spread of the virus. (Reduced community spread also helps to reduce herd-immunity "overshoot".)

* DEI can be targeted especially to high-exposure populations and individuals for whom early immunity would be especially valuable. (Think: medical workers, nursing home staff, etc.)  Another form of targeting would be like "ring vaccination" to help contain localized outbreaks, preventing them from spreading further.

Analysis / Evaluation:

* If you expect to otherwise come close to herd immunity through uncontrolled spread, then widespread DEI is very obviously superior. (An additional factor relevant to this scenario is that by targeting lower-risk populations, you can further reduce the total harm done by the virus in the course of reaching herd immunity.)  Note that this would have been the situation in the U.S., had vaccine development taken the full 18+ months that many expected early in the pandemic.

Otherwise (i.e., if vaccines would become available well before the threshold for herd immunity would otherwise be reached through natural infection):

* Targeted early DEI could plausibly still be valuable for containing outbreaks and reducing community spread, potentially reducing the total number (and likely reducing the total severity) of infections that occur.  (To help see this, consider, for any given "super-spreader", how much harm would have been prevented had that individual previously been inoculated.)  But much depends on the details, including how many "unnecessary" instances of DEI would likely occur (i.e., to someone who would otherwise have remained Covid-free) for each successfully preventative inoculation (i.e., of someone who otherwise would get Covid and even spread it to others.)

* Though we don't discuss this (in any detail) in the paper, if combined with "immunity passports", DEI could do further good by reducing the indirect harm from society's response to the pandemic, even if it didn't reduce the direct health costs of the pandemic.

The harms from the pandemic, both direct and (especially) indirect, have been so immense that the potential gains from a possible "solution" like DEI were quite extraordinary.   While one can imagine scenarios in which DEI makes things worse, it seems to me that, at least in the US, there's less scope for things to get that much worse compared to how much better they could have been. (And, of course, I think we've good reason to expect DEI to more likely be helpful than harmful.)  So it strikes me as exactly backwards that many people initially judge DEI to be "reckless".  Such a judgment seems to neglect the immense (and largely realized!) risks of allowing the pandemic to rage on unabated -- something that, I believe, should have been considered the greater risk all along.  (N.B. Just speaking for myself here, not my coauthors!)

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