Credit for the original idea comes from this thread: https://www.reddit.com/r/slatestarcodex/comments/fk5au8/corona_variolation/

The idea is to use variolation to innoculate young people and build up herd immunity to the virus. Perhaps with an infected scratch to the shin.

I imagine this would be completely politically infeasible, but ignoring that, can anyone weigh in on whether this would work or not? I thought I read somewhere that getting infected with the virus through the eyes was far less lethal than getting infected through the lungs, but I can't find the source ATM.

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I have no specific expertise here; I'm just a statistician.

I believe that if we're in this for the long haul — that is, over a year until a vacciine comes out, with responsible people spending the majority of that year in "suppression" mode according to the terminology of the Imperial College simulation — it would be beneficial for those under 30 without special vulnerabilities to be deliberately infected in a way that does not substantially spread the virus to the wider population. This would require a huge mobilization: facilities and social organization such that a bunch of kids with a few twenty-something caretakers could live (hopefully, happily) for a 6-8 weeks with absolutely minimal physical contact with people outside. That's possible to do well in principle — think summer camps — but doing it at the largest scale possible would involve big challenges, including having health care available for a bunch of sick-but-mostly-not-dying kids.

I suspect there is no way that Western societies will be able to do this at substantial scale. I would NOT suggest attempting it at individual scale. I would not be surprised to see China begin to attempt something like this. I would be surprised if they pulled it off without at least some horror stories. Those bad results might or might not be bad enough to outweigh the net good of improving herd immunity, allowing normal schooling going forward, and creating a population of under-30 immune people able to continue to work without having to worry about their own exposure (that is, about the inside of their body serving as a vector/reservoir for the virus; of course, the outside of their body would still need precautions not to be a vector).

It seems reasonable, that getting infected in the skin or eye, would give the immune system a head start, even if the virus eventually does spread to the lungs through the blood stream. When virus is shed in the lungs, it spreads through air flow, from a possible single first infection point, all throughout both lungs, in very short time. That kind of airflow acceleration of the infection does not happen if the infection happens in the eye. To develop the shades of gray, it might also be the case, that an infection in the nose, by a small dose, is far less deadly than an infection by large amount of virus in the lungs. Thus, deliberate infection seems preferable to random infection.

The process of vaccination by scratching the skin is known as:

  • "scarification"

or

  • "percutaneous vaccination"

or simply as

  • "scratch vaccination"

(unless specifically for smallpox when variolation is appropriate.)


Via the eyes would be "intraocular vaccination".