I had been wondering this too I know of one that’s in the works https://www.sciencemag.org/news/2020/02/singapore-claims-first-use-antibody-test-track-coronavi

I had been wondering this too I know of one that’s in the works https://www.sciencemag.org/news/2020/02/singapore-claims-first-use-antibody-test-track-coronavirus-infections https://www.sciencemag.org/news/2020/02/singapore-claims-fir... I have seen other talk about such tests on Twitter but it’s too difficult to find it now. Such tests seem to be called antibody tests or serological tests/assays. EDIT: this twitter thread discusses such tests https://twitter.com/nachristakis/status/1240689935557865472?s=21 https://twitter.com/nachristakis/status/1240689935557865472?...