[rolling_stone]

COVID-specific T-Cell immunity cannot be detected unless you are\actively\ fighting a COVID intrusion.

thanks

do you have more info or a source on that ?

[Cletus.D.Yokel]

Whilst looking for sauce on T-Cell immunity, I found this:
https://patch.com/us/across-america/did-you-have-covid-19-new-t-cell-test-may-provide-answer

This might tell us the answers we seek.