A reopening strategy focused on herd immunity doesn’t have to be in opposition to flattening the curve. By flattening the curve we enable herd immunity to build up at a rate which is slow by steady.
The question is what the rate is. How long will it take to develop herd immunity while maintaining social distancing?
This is a particularly important question because of political stasis. The federal government will remain broken for at least the next 12 months. No action is the most likely action. Herd immunity developing gradually out of the status quo is reasonably likely.
Update April 17: the percentage of formerly-infected, now immune, people in Santa Clara CA, which was one of the first places C19 appeared, is 2.81%. Per TPM:
If this number is close to accurate it suggests that even in a relative hotspot the population is all but untouched by the disease and thus remains almost entirely vulnerable.
The good news is that this data is very early. Also a lot depends on how much social distancing has been going on, and in this part of California the social distancing has been fairly aggressive.