The Reliability & Utility of Serological Antibody Tests in COVID-19

Overall Usefulness for Clinicians

With more information gleaned from vaccine development, it may make sense to run these antibody tests as immune markers. But at the present time, these serological antibody tests, even the high-quality ones, offer little utility to clinicians. Clinicians may do well to remember the familiar adage not to test unless the results might impact medical management.

Neither Dr. Kadkhoda nor Dr. Calabrese are choosing to recommend serological antibody assays as a part of routine testing. “I don’t want to offer the test and have the healthcare provider ask me, ‘What does this result mean?’ I wouldn’t have anything helpful to tell them,” says Dr. Kadkhoda.

If clinicians do choose to offer such antibody tests to patients, they should evaluate the regulatory status and performance characteristics of specific antibody tests used, choosing tests that have demonstrated high specificity. Clinicians must also keep in mind factors influencing the positive predictive value of the test, such as disease prevalence. Results can also be improved by focusing on people with a higher pre-test probability of having antibodies, such as people who’ve recently experienced symptoms consistent with COVID-19. Alternatively, clinicians may choose to confirm a positive result with a second test that uses different design characteristics.³

But Dr. Calabrese emphasizes that neither clinicians nor patients should overinterpret results of positive SARS-CoV-2 antibodies. “At the present time, at least until we learn more, positive serology should not cause anyone to ease up on infection prevention measures.”

Ruth Jessen Hickman, MD, is a graduate of the Indiana University School of Medicine. She is a freelance medical and science writer living in Bloomington, Ind.

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