3 ms·
> We know that almost no one has perfect pre-existing sterilizing immunity to the novel coronavirus, because we've seen highly-connected populations (homeless s
by argonaut 6y ago
> We know that almost no one has perfect pre-existing sterilizing immunity to the novel coronavirus, because we've seen highly-connected populations (homeless shelters, slums, boats, etc.) where almost everyone tested positive.
We don't actually know that. Even if some significant % of the population has pre-existing sterilizing immunity, then by chance we'd still expect to have many groups of people where everyone is vulnerable.
- tripletao 6y agoFair point. I still think pre-existing sterilizing immunity is unlikely, since (to my non-biologist's understanding) antibodies tend to be specific, and T cell immunity is broader but not usually sterilizing. The existence of those unlucky groups isn't conclusive evidence in itself, though, especially if pre-existing immunity is distributed non-uniformly (which it probably is, if there's some genetic basis, or if different strains of common cold coronavirus swept through different regions last year and primed people's T cells differently). Of course non-sterilizing immunity could still be incredibly valuable. They're speculating that the current vaccine candidates may not cause sterilizing immunity[1], but immunity that turns a fatal illness into a bad cold (or a bad cold into a couple of sniffles) is great, whether naturally pre-existing or from a vaccine. 1. https://www.statnews.com/2020/05/22/the-world-needs-covid-19-vaccines-it-may-also-be-overestimating-their-power/ https://www.statnews.com/2020/05/22/the-world-needs-covid-19...