The first strategy leaves you with a huge population of people with no immunity to the virus, which means you have to keep holding the lid on it indefinitely or you’re back to square one.
In the second strategy, everyone ends up either immune or dead, which doesn’t mean the virus is gone—it will remain endemic—but there will be no giant flood of new cases when people resume their lives.
(Obviously it’s not quite as simple as that if the virus doesn’t generate durable immunity. Then you end up with something like the flu, where partial immunity keeps it vaguely tamped down with occasional flares.)
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.
The first strategy leaves you with a huge population of people with no immunity to the virus, which means you have to keep holding the lid on it indefinitely or you’re back to square one.
In the second strategy, everyone ends up either immune or dead, which doesn’t mean the virus is gone—it will remain endemic—but there will be no giant flood of new cases when people resume their lives.
(Obviously it’s not quite as simple as that if the virus doesn’t generate durable immunity. Then you end up with something like the flu, where partial immunity keeps it vaguely tamped down with occasional flares.)
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.