I think we know too little. The Nature article is completely unhelpful. The LessWrong post is not particularly useful.
From everything I have seen, the risks to kids of Covid are on the order of the risks of a home with a swimming pool. And no one freaks out about sending their kids to friends homes with swimming pools. At this level, even if the vaccines are very safe it likely doesn’t make sense. The logic is that a kid has a diminishing chance of exposure to the disease with a very small chance of serious consequences from getting that disease, compared to a 100% chance of being exposed to the very small risks of the vaccine. I’m interested in having this intuition proven wrong, though.
I also don’t buy that there is a causal relationship between high living costs and high homelessness. As a Bay Area resident, it’s pretty clear that people don’t go from “can’t afford a home” to “homeless” – they go from “can’t afford a home“ to ”resident of Boise”.
Someone else made this point on a post I read recently, but I can’t remember where (Maybe it was Bryan Caplan?) But it extends the observation above as follows:
The Bay Area (and other high-cost areas) are, all else being equal, desirable places to live. People don’t live here primarily because it is too expensive to have a decent quality of life here.
A homeless person, however, gets to live here (i.e., a “nice” place to live) without having to face the high housing costs, because they don’t pay those high housing costs.
That seems like a semi-plausible explanation of why high housing costs would be correlated to high homelessness without causing that homelessness.