I know that it doesn't mean that he isn't protected, but I didn't find data on the protection against severe covid disease with the conditional probability of s

I know that it doesn't mean that he isn't protected, but I didn't find data on the protection against severe covid disease with the conditional probability of spike specific antibody test being negative after being properly vaccinated. Instead of just guidance I would like to see data. Anyways that's why there are specific, slower test that can test his protection against specific virus mutations.