R in most US states right now is closely clustered around 1. Mutant strains are more contagious, enough to bring the R0 up to 1.5 or so. But having a lot of the population vaccinated will bring it back down again. Also, I’m acting like there’s some complex-yet-illuminating calculation we can do here, but realistically none of this matters. It’s not a coincidence that all US states are closely clustered around 1. It’s the control system again – whenever things look good, we relax restrictions (both legally and in terms of personal behavior) until they look bad again, then backpedal and tighten restrictions. So we oscillate between like 0.8 and 1.2 (I made those numbers up, I don’t know the real ones). If vaccines made R0 go to 0.5 or whatever, we would loosen some restrictions until it was back at 1 again. So unless we overwhelm the control system, R0 will hover around 1 in the summer too, and the only question is how strict our lockdowns will be.
In autumn, if we haven’t already vaccinated everyone there’s a risk things will get worse again because of the seasonal effect. Also, for all we know maybe the virus will have mutated even further and become even more vaccine resistant. Now what?
Author(s): Scott Alexander
Publication Date: 15 February 2021
Publication Site: Astral Codex Ten at Substack