R0 above 1 means there's a doubling rate. A doubling rate means it doubles within a period of time. Let's arbitrarily pick 10 days as a doubling rate. If, at

R0 above 1 means there's a doubling rate. A doubling rate means it doubles within a period of time. Let's arbitrarily pick 10 days as a doubling rate. If, at a time when the doubling rate was 10 days, a particular mitigation measure had been taken, sufficient to knock R0 below 1, ten days earlier than it actually happened, then for the population in question, the situation is half as prevalent. Project that forward, everything that happens since that point flows from a situation that is half of what it actually was. It's a huge difference. The situation isn't discrete, it's continuous. Getting hung up on 100% prevention is beside the point. Knocking it back by 50%, or even 20%, or 10%, is huge compared to the alternative. People check the weather every day. I wish our nation had developed a very clear signal that everyone could check every day. Just check it in the morning to know whether it's advisable to wear a mask that day. Back in the post-Delta pre-Omicron days, I did a project of my own to develop something I could check every day. (https://tunesmith.github.io/covid-dashboard/ https://tunesmith.github.io/covid-dashboard/) It's messy and hacky and some of its math is out of date and I haven't gotten around to updating it for omicron, but imagine something like that that is funded, tailored for everyone's county, and really easy to report and communicate. It would have helped, just to know whether today is a mask day or not.