The Immunity Treadmill: How covid-19 vaccine resistance could perpetually push herd immunity out of reach

Collective resistance depends on how many unvaccinated people have already been infected, how many of them have immunity, and where they live.

I am sitting at a bar in Washington, DC waiting to get drinks and an early with an old friend. Everyone around me looks awkward. People are standing ever-so-slightly farther away than they did In The Before Time. Hand sanitizer comes in and out of purses like people are (still) avoiding the plague.

I’m sure I look off too; many of us haven’t been out to …