Testing Update: There are now more commercially available antibody tests for SARS-CoV-2 than any other infectious disease. Many of the 200 new tests on the market (or in development) are worthless. Here's what happened:
In the race to create more testing options, the FDA made an important decision: It allowed internal validation of new antibody diagnostics. Translation: FDA didn't review performance metrics; it simply relied on companies to say their new antibody test works. That's a problem:
SARS-CoV-2 is not the only coronavirus; there are several others circulating around the world. Most adults have antibodies to one of them. We don't yet know if new tests for SARS-CoV-2 antibodies will cross-react (interfere) with antibodies from other coronavirus infections.
This impacts research, too. When results are released, we must scrutinize the antibody test that was used. A study from Santa Clara suggested infection rates 50 -85 times higher than documented. A key critique of that study was the antibody test they used: the-scientist.com/news-opinion/h…
Key point: Antibody tests are not immunity tests. They simply determine if someone has been exposed to #coronavirus. To get immunity, you don't just need an antibodies, you need a *neutralizing* antibodies. Most commercially-available tests can't tell the difference.
Earlier this week, the FDA resumed its usual role in oversight. Companies must now submit validation data within ten days or face removal from the market. Many of these tests won't withstand the scrutiny.
