i don’t see how it’d be wasteful to know how many people have natural immunity. seems quite useful actually even if we determine they should still get vaccine
In a country as large as US it would be enough to test probably one in 10 thousand people to get accurate statistics.
https://www.ons.gov.uk/peoplepopulationandcommunity/healthan...
Unfortunately that never really happened in the US. There were a few small seroprevalence studies in limited areas at specific times but nothing consistent on a nationwide basis.
Also note that there is more to immunity than antibodies, so assaying antibody levels alone will underestimate the level of immunity in the population. We should also be testing memory cell activity now that a test is approved.
https://www.fda.gov/news-events/press-announcements/coronavi...