I haven’t understood the real use of a test for the active disease. You could be negative one day, and contract it a day or two later. Are we going to test everyone, endlessly?
We need an accurate antibody test to gauge how many have actually had it, and possibly have had it with no symptoms. It seems that would give more accurate data on just how dangerous this truly is. I suspect that many have been infected without ever knowing it - and perhaps earlier than we know.
But, I’m not a scientist. I don’t fully understand the difference between antibody and antigen tests; or how long after disease they can detect that one has had it. And I suspect that they can be as erroneous as the PCR test.
Yes, it’s been so confusing. First they say they have antibody tests, but, oh wait, they aren’t that accurate. I really want to have one, because I strongly suspect I had this virus in February.
Here is more info on antibody tests. It’s not very encouraging.
https://www.cdc.gov/coronavirus/2019-ncov/testing/serology-overview.html