They've flopped back and forth. The simple truth is there is no other practical way to establish immunity. Like re-defining herd immunity as only a very as a certain number of vaccinated people, the not using antibody tests for establishing immunity makes it so those who got covid and recovered can't use that to assert immunity.

Ironically this is after a year of doing antibody testing to established convalescent plasma donors...and plasma therapy worked somewhat.

They've flopped back and forth. The simple truth is there is no other practical way to establish immunity. Like re-defining herd immunity as only a very as a certain number of vaccinated people, the not using antibody tests for establishing immunity makes it so those who got covid and recovered can't use that to assert immunity.