[michaelmrose]

Nobody credible believes 20-25% is a likely threshold for herd immunity. You cannot Realistically in America isolate the old from the young and if the young spread it like wildfire the old get sick.

Literally everything in your post is as poorly considered. It's important not to spread misinformation.

[T-hawk]

It's 20%-25% of currently detectable antibodies, coupled with another 20%-50% from prior coronaviruses or other cross-immunity. That's the important distinction. The sum approaches the 50%-70% needed for herd resistance based on 1-1/R0. That's the point of this article.

[michaelmrose]

A couple people suppose is not the same as proof

[millettjon]

See: https://www.news-medical.net/news/20200731/Research-suggests...

In addition to immunity based on T cells, the HIT depends on how individuals are networked. The original 60-70% estimates were based on 100% of people being vulnerable and also a random distribution of individuals interacting. In reality a small fraction of the population will have many interactions and once they become immune those transmission vectors away and the average R number drops. So based on the latest research plus observations of the worst hit places, 20-25% seems plausible.