Antibody testing is not the only method. There is a much more expensive T-cell testing, that can also confirm prior infection. None of the tests are approved by FDA for the purpose of determining natural immunity.
They are emergency authorized for verifying prior infection, though. As far as I can tell, they constitute medical proof of natural immunity in some capacity, but the test itself can’t tell you to what extent that natural immunity is protective.
However, the studies I looked at on natural immunity show it seems to be about 80% effective at preventing infection, median 7 months after infection (https://pubmed.ncbi.nlm.nih.gov/33844963/), so that + an anti-body test to confirm I really had it seems sufficient.
Antibody testing is not the only method. There is a much more expensive T-cell testing, that can also confirm prior infection. None of the tests are approved by FDA for the purpose of determining natural immunity.
They are emergency authorized for verifying prior infection, though. As far as I can tell, they constitute medical proof of natural immunity in some capacity, but the test itself can’t tell you to what extent that natural immunity is protective.
However, the studies I looked at on natural immunity show it seems to be about 80% effective at preventing infection, median 7 months after infection (https://pubmed.ncbi.nlm.nih.gov/33844963/), so that + an anti-body test to confirm I really had it seems sufficient.