* Washington Post…

The Food and Drug Administration, under fire for allowing more than 100 commercial coronavirus antibody tests on the market without review, moved Monday to assert oversight, saying the tests will have to pass agency muster, including meeting standards for quality and accuracy.

Officials said “unscrupulous actors” have been “marketing fraudulent test kits and using the pandemic as an opportunity to take advantage of Americans’ anxiety.”

The FDA action came after the agency was criticized for a March 16 policy that allowed commercial test makers to sell antibody tests after validating their own data and notifying the FDA. The result, some testing experts said, was a flood of products of dubious quality that confused hospitals, doctors and consumers — “a wild, wild West” environment, said Scott Becker, chief executive officer of the Association of Public Health Laboratories, which represents state and local public laboratories. He and others in the laboratory field urged the agency to exert its authority over the tests.

Antibody, or serology, tests are designed to identify people who may have overcome covid-19, the disease caused by the novel coronavirus, including those who had no symptoms, and developed an immune response. They are not designed to detect active infections. Some officials tout the blood tests as a way to identify people who have developed immunity and can safely return to work. But many scientists say evidence is lacking that the tests can prove someone has immunity from the coronavirus or for how long.

FDA Commissioner Stephen Hahn emphasized those uncertainties in a Monday call with reporters. “Whether a test should be a “ticket for someone to go back to work as the sole item, my opinion on that would be no, because there are a lot of unanswered questions,” he said.

Go read the whole thing. Insane.

* And while we don’t even know how immune people are after they’ve been infected, having reliable tests is important for another reason…

The tests might also be used to identify potential donors of “convalescent plasma,” an approach in which blood plasma containing antibodies from a recovered individual is used to treat a Covid-19 patient, the F.D.A. said.

* Politico…

Last week, the American Medical Association called on HHS to restrict use of antibody tests to health providers trained to interpret their results and in epidemiological studies due to “growing concern” about the performance of several tests on the market. Until more is known about whether survivors of coronavirus infection emerge with any degree of immunity, people should not use the antibody tests to guide their decisions on physical distancing, the physician group cautioned.

The senior FDA official said the agency has had discussions with the AMA and hinted that government guidelines on the appropriate usage of antibody tests are forthcoming. Several members of the White House coronavirus task force have said it might be necessary for people to receive two antibody tests to cut down on the potential for unreliable results.

“Even a high-performing antibody test when used on individuals in a population that does not have many cases of COVID-19 infection — a population with low prevalence — may produce as many or more false results as true results because the likelihood of finding someone who has been infected is very small,” Shah and Shuren wrote. “This doesn’t mean the test is bad, but rather recognizes the inherent limitations of these kinds of tests.”