CHICAGO — The American Medical Association is issuing guidance to help physicians and the public understand the potential uses and limitations of antibody testing for COVID-19.
The AMA says the guidance comes after a growing number of tests claiming to identify people who have been exposed to the virus and who are potentially immune. The association cautions physicians and the general public about using these to determine COVID-19 immunity and warns that people should not stop social distancing on the basis of antibody test results.
AMA President Patrice A. Harris, M.D., M.A. says that given there is no scientific evidence yet showing if, when, and for how long a person might become immune to COVID-19, physicians and the general public should not use antibody testing to consider anyone immune.
“Although many are using these tests to determine whether an individual had COVID-19, we encourage physicians to only use antibody tests authorized by the Food and Drug Administration (FDA) and only for the purposes of population-level studies, evaluating recovered individuals for convalescent plasma donations, or along with other clinical information as part of a well-defined testing plan for groups or individuals,” said Harris.
The AMA’s new guidance provides an overview of the current state of antibody testing, including their limitations, potential uses, and how they are and are not regulated. This guidance can be found online as part of the AMA COVID-19 Resource Center.
The association says that while these tests may play an important role in determining the overall prevalence of COVID-19 in the U.S. population, including asymptomatic infection, limitations exist in using them to identify prior infection in individuals. Many currently on the market may return a significant number of false-positive results, as well as show cross-reactivity—meaning the tests also identify antibodies for other coronaviruses, such as those causing the common cold.
There are also concerns about the performance and fraudulent labeling of many SARS-CoV-2 antibody tests currently available, says the AMA. The vast majority of more than 120 tests available have not been authorized by the FDA, despite marketing claims saying otherwise. The AMA says it urges physicians to pay close attention to the regulatory status of all available antibody tests. A list of all COVID-19 antibody tests authorized by FDA can be found on FDA’s website.
The AMA still recommends social distancing to reduce the spread of COVID-19. However, there are marginalized patient-communities disproportionately impacted and their housing or employment status may make it difficult to practice social distancing. The new guidance calls for providing messaging to medically underserved communities that explicitly take into consideration cultural and social features affecting their ability to make long-term choices on social distancing and other COVID-19 precautions.