Right, yes, agreed and good point—my understanding is that a naive epidemiological model gives a fraction of 1 - (1/R_0) of the population needing to be infected, to drive the effective value of R (new transmissions per infected person) below 1, at which point the population can no longer sustain epidemic spread.
Clarification: you don’t need everyone to be immune or dead. Just enough people that the remaining population can’t sustain a continuous epidemic.
Right, yes, agreed and good point—my understanding is that a naive epidemiological model gives a fraction of 1 - (1/R_0) of the population needing to be infected, to drive the effective value of R (new transmissions per infected person) below 1, at which point the population can no longer sustain epidemic spread.