(1) NYC’s response was virtually identical to CA, some aspects were delayed by a few days, others happened earlier (closures of public gathering places in New Rochelle). I suspect that the outbreak was seeded there by people returning from Europe and China … a lot of the cases are around JFK, likely coming from airport employees. Density also didn’t help.
The good thing is that there’s some news that an insanely high number of people have active infections where testing is universal (~15% of women coming in to the delivery ward in some hospitals) … since we’re not counting cleared infections, the true attack rate could be much higher. If we’re at 50%, we’re well on the way to herd immunity. Only antibody testing will tell for sure…
(2) Antibody testing’s accuracy still stinks (60% if you’re unlucky, 90% if lucky). It’s not useful as a tool for telling people to go back to work, but it is a useful tool in telling POPULATIONS how close they are to mass immunity.
(3) One idea would be not to reopen schools, but reopen summer camps early for healthy kids, and maybe subsidize tuition. Use staff that are young and/or already recovered. The kids (~20% of the population) can pass the virus around, move towards herd immunity, while not risking infecting grandma and grandpa. Of course, it’s an open question whether kids shed virus after recovery, and for how long…
(4) Assuming most people develop immunity and clear the infection, why would infection be a scarlet letter?