Does Vaccinations Plus Cases Equals Population Immunity in Arizona?
On Monday I did a post worrying about Arizona's falling vaccination rate. I showed a curve suggesting that if things keep going the way they are now, the percent fully vaccinated might level-off well before we get to 50% of the population. In a conversation about that with some public health people I know, it was pointed out that we also have to take previous cases into account when considering the percent who make have some level of immunity. Having had and recovered from COVID-19 give you some immunity, but not as much as if you're fully vaccinated. The thinking seems to be that having a case is somewhat similar to one dose of a two-vaccine regimen. But there are problems with rolling infection-based immunity together with vaccinations to estimate what percent of the population is protected. For one thing, many people who have had COVID-19 have also gotten vaccinated. Some researchers I know who recently completed a nationwide study told me that ...