If the number of direct tests has exploded, then the number of indirect tests is like a star going supernova. While only four have received an Emergency Use Authorization from the FDA, the agency says it has been notified by 98 test developers that they are offering tests for sale. That’s significant because of the approach the FDA is taking to new indirect tests. Usually, companies would have to go through years of research to prove, document and verify the quality and effectiveness of a new test before it could earn FDA approval. Now, though, the agency is allowing the entire approval process to be sidestepped, saying it won’t object to any new test being used by the public so long as the developers tell the FDA about their test and don’t try to make false claims about what it can do. If they want to get an EUA, the developers can voluntarily document how well their test works and send the data to the FDA — after the test is already in use.

These indirect tests are crucial, experts told me. They can turn up a false negative if you take them too soon, without giving your body enough time to build up antibodies. But they’re the tool epidemiologists need in order to get a better handle on how many Americans are actually contracting this virus, and who has and hasn’t built up some level of immunity.

That means dozens of tests — not including the four tests with an EUA — are being sold despite never having submitted data to the FDA to show how well they work (or even prove they do).