The U.S. Food and Drug Administration (FDA) is planning to take action against companies that are making false claims about serological tests for SARS-CoV-2/COVID-19 or are marketing tests that are not accurate and reliable.
Some firms are falsely claiming that their serological tests are FDA-approved or authorized, or falsely claiming that they can diagnose COVID-19, FDA Commissioner Dr. Stephen Hahn explained in a statement.
Polymerase chain reaction (PCR) testing is the standard for diagnosing SARS-CoV-2, but antibody tests are now emerging and hold promise for showing who has had past exposure and an immune response. The FDA has an emergency use authorization (EUA) review process for tests but also allows companies and labs to offer testing outside of that pathway, following a relaxation of regulations last month.
Hahn stressed that serological testing tests for an immune response to the infection -- not the coronavirus itself.
"In the early days of an infection when the body's immune response is still building, antibodies may not be detected," Hahn wrote. "This limits the test's effectiveness for diagnosing COVID-19 and is why it should not be used as the sole basis to diagnose COVID-19."
To date, more than 70 test developers have notified the agency that they were making a serological test available, but only one has received an emergency use authorization, the FDA noted. Cellex received an EUA on April 1 for an immunoglobulin G/immunoglobulin M (IgG/IgM) blood test.