The Food and Drug Administration announced on Monday that companies selling coronavirus antibody tests must submit data proving accuracy within the next 10 days or face removal from the market.
The antibody tests are an effort to detect whether a person had been infected with the coronavirus, but results have been widely varied and little is known about whether those who became ill will develop immunity and, if so, for how long.
Since mid-March, the agency has permitted dozens of manufacturers to sell the tests without providing evidence that they are accurate — and many are wildly off the mark.
The F.D.A.’s action follows a report by more than 50 scientists, which found that only three out of 14 antibody tests gave consistently reliable results, and even the best had flaws. An evaluation by the National Institutes of Health has also found “a concerning number” of commercial tests that are performing poorly, the agency said.
Around the globe, government and health officials have hoped that antibody tests would be a critical tool to help determine when it would be safe to lift stay-at-home restrictions and reopen businesses. The highly infectious Covid-19 disease has now killed nearly 70,000 people and sickened more than 1.1 million in the United States alone.
While 11 companies have been given F.D.A. clearance to sell the antibody tests, many other products do not have agency authorization. The result has been a confusing landscape in which tests by established companies such as Abbott Laboratories, Cellex and most recently, Roche Diagnostics, are competing with unapproved tests made by unknown companies and sold by U.S. distributors with spotty track records.
In a statement on Monday, Dr. Anand Shah, the F.D.A. deputy commissioner for medical and scientific affairs, and Dr. Jeffrey Shuren, director of the Center for Devices and Radiological Health, defended the agency’s initial policy saying the tests were never intended to be used as the sole basis for determining whether anyone had been infected.
“We unfortunately see unscrupulous actors marketing fraudulent test kits and using the pandemic as an opportunity to take advantage of Americans’ anxiety,” they said in the statement. “Some test developers have falsely claimed their serology tests are F.D.A. approved or authorized. Others have false claimed that their tests can diagnose Covid-19 or that they are for at-home testing.”
Dr. Shah and Dr. Shuren also pointed to the N.I.H. evaluation that showed a number of tests producing faulty results. The F.D.A. declined to provide details on the number of tests that were studied, or how many did not work. They also said that the F.D.A. is reviewing more than 200 antibody tests to determine whether they work well enough to get the agency’s go-ahead.