@MartinKulldorff Would you mind answering a question? Does r0 drop the closer a population gets to herd immunity? In other words, the closer we get to 60%, the slower the virus will spread?
R0 is by definition the reproduction number at time 0 when nobody has immunity. But, you are correct that the effective reproduction, R, will drop as we get closer to herd immunity. It will also decrease (increase) with increased (decreased) social distancing and home isolation.
