[tzs]

What about people born after that point? As immune people die over time from other causes, and as people are born without immunity, the percent of the population with immunity from having had it falls.

Non-vaccine acquired herd immunity is temporary.

[TuringNYC]

I think the idea is that once there is herd immunity, the virus has no way to propagate and ends up disappearing w/o vectors. However, that would require global immunity.

[yoz-y]

You are right, I haven't thought about that.