After allowing unreviewed antibody tests to pervade the U.S. market for weeks, the FDA is closing its open-door policy for coronavirus blood serology tests—bringing their oversight more in line with the molecular diagnostics used to confirm active cases of COVID-19.
Since mid-March, the FDA has let manufacturers distribute unauthorized antibody tests, provided they validate the tests themselves and do not advertise them as a standalone method of diagnosing a patient. Instead, they could be used to track the spread of the virus through the population, by detecting signs of an immune response to a previous infection.
However, both the demand and reliance on these blood tests have grown, as more governments have incorporated widespread serology testing—and the potential of antibodies to bring immunity to the coronavirus—into strategies for removing lockdowns and reopening their economies, by allowing people with some level of protection to return to work.
These tests could also be used to identify people who have recovered from the disease as potential donors of convalescent plasma, which could be used to treat others.
In the U.S., several dozen test manufacturers, many from China or overseas, had notified the FDA of their intentions to sell about 170 different antibody diagnostic products in the country without seeking an agency authorization. Several more U.S. laboratories have developed their own internal blood tests.