Make Sure Patients Understand: Antibody Tests Don’t Signal the End of Protective Measures

Some television news reports make it seem as if antibody tests for COVID-19 will be the key to reopening the economy and diminishing restrictions about group gatherings and protective measures in public spaces. A Forbes magazine piece penned by an infectious disease expert notes that the best response to that idea is probably, Not so fast. In the article, Matthew Binnicker, PhD, director of clinical virology at the Mayo Clinic, acknowledges that while serology tests are helpful in identifying people with antibodies against SARS-CoV-2, “there are important limitations.” For one, he writes, such tests are not 100% specific and are therefore prone to false-positive results. Further, the idea that the presence of antibodies indicates immunity from infection or from infecting others is not a given. “Past experience with other coronaviruses, including those causing the ‘common cold,’ has shown us that the immunity conferred by infection is not lifelong…. We can experience multiple bouts of the common cold because the immune response to these coronaviruses is relatively short-lived, often in the range of several years.” (The difference being, of course, that the common cold doesn’t kill 100,000-plus Americans in a single season.) So, in your role as a public health educator, consider cautioning patients that while a positive antibodies test may mean you’re at lower risk for re-infection with COVID-19, it doesn’t mean it’s time to leave your mask at home.