NEW YORK — Antibody testing for SARS-CoV-2 remains inappropriate for guiding individuals' decision-making about the ongoing pandemic, in part due to the presence of ineffective tests on the market, a panel of four medical experts said during a congressional subcommittee hearing held on Tuesday by video.
"Many people mistakenly view antibodies as a 'get-out-of-jail-free' card to return to normal life — a dangerous misconception used as a selling point by bad actors," Representative Raja Krishnamoorthi (D-Illinois), chair of the Subcommittee on Economic and Consumer Policy, said during the briefing. "A lot of the [antibody] tests simply don't work that well; even tests meeting FDA's standards can be false more than half of the time, especially if the prevalence of COVID-19 in the surrounding population is low."
"Even with a true positive, scientists are not sure even what that means" in regards to immunity, he said.
During the briefing, Johns Hopkins University researcher Gigi Gronvall told members of the subcommittee that antibody tests are useful for public health agencies performing population-based prevalence studies, helping to understand true case fatality rates and the effects of mitigation strategies.
But these tests should not be used to determine immune status and should not inform return-to-work schemes or to manage residential populations, according to the panel. "Serology tests have a number of limitations that may result in actual harm to public health," Jesse Ehrenfeld, chair of the American Medical Association's board of trustees, noted. The high risk of false positives associated with many available tests, for instance, could lead to the exposure of a vulnerable person to the virus.
Further, antibody tests cannot be used to determine an individual's immunity to SARS-CoV-2 and whether they are protected from subsequent infection, Jennifer Rakeman, assistant commissioner of the New York City Department of Health and Mental Hygiene, added.
Georgetown University's Jesse Goodman, a former US Food and Drug Administration chief scientist, said that the US Food and Drug Administration's move in March to allow the sale and use of SARS-CoV-2 antibody tests when such testing is performed in a lab or by healthcare workers at the point of care led to a flood of antibody tests from both qualified and unqualified groups.
While the FDA began requiring in May that antibody tests obtain Emergency Use Authorization (EUA), Goodman said that problems remain and called for a prioritized review of high-risk tests by the agency.
In vitro diagnostics trade organization AdvaMedDx pushed back at the panel's statements, however, issuing a statement calling antibody tests "essential tools" for both patients and frontline workers.
AdvaMedDx noted that since the FDA began requiring manufacturers of SARS-CoV-2 antibody tests to obtain EUA, "diagnostic test manufacturers are delivering millions of these high-quality, highly sensitive, and specific tests each month, and they are all validated to FDA's exacting standards."
In addition to helping clinicians and public health experts prevent, detect, and treat COVID-19, antibody tests "facilitate the critical work of assessing individual and population-based immune response, while also supporting employer workforce testing programs," AdvaMedDx said. "Patients and frontline clinicians alike expect and deserve the high-quality, reliable coronavirus tests provided by America's innovative diagnostics industry."