Snorting powdered smallpox scabs and jumping into the beds of those freshly dead from yellow fever. Humanity has gone to extreme lengths in search of immunity before.
This video is a collaboration between Scientific American and Retro Report:
It shouldn’t be called an immunity test to begin with. It is an antibody titer and type test. The same type of test is used to determine if someone is HIV positive, but the presence of anti-HIV antibodies does not make people immune to HIV.
With that being said, it is expected that anti-SARS-COV2 antibodies will provide protection in the vast majority of cases, but caution is always needed when dealing with newly emergent and novel viruses.