Faulty COVID-19 antibody tests made it to US market, FDA says. What about the results?
Antibody tests help track who has been exposed to the novel coronavirus — but not if the test is wrong.
The U.S. Food and Drug Administration on Monday clamped down on companies selling antibody tests, also known as serological tests, after lax regulations early in the pandemic allowed for unauthorized tests to flood the market.
Now companies have 10 days to to submit proof their tests work, lest the FDA pull them from the market.
“Flexibility never meant we would allow fraud,” the agency said in a statement. “We unfortunately see unscrupulous actors marketing fraudulent test kits and using the pandemic as an opportunity to take advantage of Americans’ anxiety.”
That includes companies falsely declaring their tests are FDA approved and available for at-home testing or diagnostic use. Others “are performing poorly” based on independent evaluations, according to the FDA.
How we got here
Antibody tests determine whether someone has been exposed to the coronavirus and developed antibodies against it, the FDA says. They can help track asymptomatic cases and also identify potential plasma donors to help treat infected patients.
When the FDA issued its initial policy on antibody tests in the U.S. on March 16, the agency said a “higher level of flexibility” was necessary. The tests were never intended to diagnose COVID-19 — nor were they designed for at-home use, according to the FDA.
As a result, “dozens of manufacturers” were allowed to sell their tests “without providing evidence that they are accurate,” The New York Times reported.
Some tests manufactured in China and later rejected by the UK and Indian governments because of inaccuracies are still available in the U.S., according to Buzzfeed News.
But under the new guidelines, the FDA requires companies submit requests for Emergency Use Authorization and validation data within 10 days. The agency has also issued “performance threshold recommendations” for developers to meet.
The FDA will make information public on those who are marketing tests but don’t comply with the 10-day requirement.
Future of antibody testing
Scientists have cautioned being overly reliant on antibody tests.
The FDA isn’t sure whether antibodies equate “full protection from reinfection” or how long that immunity might last, according to McClatchy News.
“All tests can provide at least some false results,” the FDA said Monday.
False results don’t necessarily indicate a “bad test,” according to the agency, just that there are “inherent limitations” to these kinds of tests.
Pathologist Alan Wu at the University of California San Francisco said mass screening with antibody tests would be “premature,” and infectious disease specialist Chaz Langelier said it’s unclear how “positivity correlates with immunity.”
“I think it’s important to know that early during infection, a negative antibody test does not mean someone is uninfected and that it takes time to develop an antibody response,” Langelier said.
In the meantime, the FDA said test results should be taken with a grain of salt.
“Those who use an antibody test need to understand its limitations and use test results as just one piece of data to inform decision making,” the agency said.
This story was originally published May 4, 2020 at 7:15 PM with the headline "Faulty COVID-19 antibody tests made it to US market, FDA says. What about the results?."
