Maybe a minor point, but to reiterate my previous comment, Christian Althaus’s formula (for transmission advantage via immune evasion) assumes a homogeneous population. Really we should be thinking of a sector of the population that has lots and lots of close contact with other people (thanks to work-situation / living-situation / etc.), and those people are disproportionately immune (naturally or via vaccination). So immune-escape implies very rapid spread, more rapid than you’d think just going by the “fraction of the population who is immune” numbers, IIUC.
(In other words, the fraction of South Africans who are immunologically naïve would be interesting to know, but also potentially misleading … We may also be interested in the fraction of South Africans who are immunologically naïve, weighted by how much close contact each person has with other people. That’s bound to be a lower number.)
Maybe a minor point, but to reiterate my previous comment, Christian Althaus’s formula (for transmission advantage via immune evasion) assumes a homogeneous population. Really we should be thinking of a sector of the population that has lots and lots of close contact with other people (thanks to work-situation / living-situation / etc.), and those people are disproportionately immune (naturally or via vaccination). So immune-escape implies very rapid spread, more rapid than you’d think just going by the “fraction of the population who is immune” numbers, IIUC.
(In other words, the fraction of South Africans who are immunologically naïve would be interesting to know, but also potentially misleading … We may also be interested in the fraction of South Africans who are immunologically naïve, weighted by how much close contact each person has with other people. That’s bound to be a lower number.)
Or sorry if I’m confused.