FDA tries to rein in ‘wild west’ of COVID-19 tests

“Save your business while saving lives,” reads the website of Because Health, a Seattle tech startup selling two types of tests to employers willing to pay $350 a pop to learn whether their workers have been infected with COVID-19.

The “Workplace Health” plan includes not only nasal swab tests to detect infection, but also blood tests aimed at indicating whether workers have developed antibodies to the virus - and, possibly, future protection.

“There’s a tremendous consumer demand,” said Dr. Lars Boman, the Boston-based medical director for the firm. “Can they return to work? Can they return to life?”

What the website does not make clear, however, is that public health officials have explicitly warned that antibody tests should not be used to make decisions about workplace staffing.

“This is a personal choice of the business, of the consumer,” Boman said.

Across America, untold numbers of employers, employees and ordinary citizens are turning to a slew of sometimes pricey new COVID-19 blood tests. Knowing who’s already been infected could have important implications for understanding the spread of the disease, scientists say. But serious questions about the accuracy of some of the serology tests - and the usefulness of the results they provide - have prompted the federal Food and Drug Administration to try to rein in what several infectious disease experts described as “the wild, wild

West” of antibody testing.

“It does look as if companies sprang up overnight both importing these tests and distributing them,” said Dr. Michael Busch, director of the nonprofit Vitalant Research Institute in San Francisco. “It’s outrageous that people were trying to make money off of this fear.”

More than 200 tests have flooded the market in a matter of weeks, promising to detect antibodies, which are proteins that develop in the blood as part of the body’s immune response to an invading virus. These are different from the molecular tests, typically done with nasal swabs, used to diagnose infection.

As of June 1, only 15 antibody tests had received FDA “emergency-use authorizations,” which allow tests that haven’t been fully vetted to be used in a crisis. Even that standard has become a selling point for some large companies, such as LabCorp and Quest Diagnostics, which emphasize that they rely on tests that have received the FDA nod.

In late May, the FDA removed more than 30 serology tests from a list of commercially available kits, saying they “should not be distributed” for sale. Removal could result from a manufacturer not submitting an emergency-use authorization request within a “reasonable period of time,” or if the test shows “significant problems” that cannot be or have not been addressed in a timely manner, the agency said. The manner of enforcement remains unclear.

Last month, the CDC issued new guidelines warning that, given the low prevalence of the virus in the general population, even the most accurate tests could be wrong half of the time.

“Serologic test results should not be used to make decisions about grouping persons residing in or being admitted to congregate settings, such as schools, dormitories, or correctional facilities,” the guidelines state. “Serologic test results should not be used to make decisions about returning persons to the workplace.”

Such tests are most useful for understanding the epidemiology of the virus, not for making individual decisions, said Dr. Mary Hayden, director of the division of clinical microbiology at Rush Medical Laboratories in Chicago. Even the best tests can’t yet answer the crucial question about whether antibodies confer immunity from future COVID-19 infections, Hayden said.

“The best possible scenario is that people get infected and they have protective immunity for a long time,” she said. “That would be awesome. But we just don’t have that right now.”

Unreliable results worry Dr. Jeff Duchin, the public health officer for Seattle and King County, Washington, where the first surge of COVID-19 cases emerged in the U.S. A person who tests positive for antibodies that don’t exist may mistakenly believe he or she is free to ignore guidance about preventing infection, potentially spreading the disease. “Regardless of whether you test positive or negative, the workplace still needs to take steps,” he said. “They shouldn’t think a testing program in any way relieves them of that responsibility.”