It's an s shaped curve, but we don't know the upper magnitude of that curve. A large percentage of the population would have to get infected in order to run the COVID out of new recruits. If it tops out at 50% of the population, that's a disaster.

Forcing the doubling rate to decrease short of hitting that point requires something else to happen. South Korea clearly did something other than running itself out of cannon fodder.

> as a higher percentage of people have or have had the virus, the growth rate decreases because there are less people available to infect

That is what you would call "herd immunity" and no, current numbers of recovered patients are not even close to have it. It doesn't happen like magic like some politician wants to make people believe, and current estimations for COVID _herd immunity threshold_ are 29%-74% of the community [1]. Make a count of that on the US population.

[1] https://en.wikipedia.org/wiki/Herd_immunity#Mechanics

Sure, but the comment I was replying to was suggesting that in 10 weeks, 300 million Americans would be infected... that is 91% of the population of the United States. We aren't going to hit that number.

The growth is not going to be that much, sure, but because we slow it down with isolation, not because the immune people stop it from spreading.

Yes... but even if we did nothing, we are unlikely to hit 90% infected... 60 to 70% yes, but not 90%.

I am not saying that is ok, or that we should just let it run its course... just that saying we will hit 90% infection is unrealistic.

I already baked that in by starting with a low infection rate (2x per week instead of 2x every 3 days).

Yes, but 90% is an unrealistic infection number no matter what you start with. I think most experts had it at around 60-70% if we do nothing.

That is not acceptable, either, given the fatality rate and the strain it would put on hospitals... but I think it is important we try to be accurate.