CDC: Antibody Tests For COVID-19 May Not Always Give Correct Results

Antibody tests may not always accurately identify a previous coronavirus infection. That is according to new guidance from the Centers for Disease Control and Prevention (CDC) that says government officials should not rely on such tests to guide policies amid the COVID-19 pandemic. 

Antibody tests, also known as serologic tests, mainly help aim to find remnants of immune response to an infection. But the CDC said the approach is wrong up to half the time. 

The agency issued the new guidance amid the growing call for massive testing for coronavirus in the U.S. and other countries. Authorities hope that finding those who had or are still infected with the COVID-19 could help in reopening plans since they could determine at-risk communities.

"Serologic test results should not be used to make decisions about grouping persons residing in or being admitted to congregate settings, such as schools, dormitories or correctional facilities," the agency stated on its website. "Serologic test results should not be used to make decisions about returning persons to the workplace."

Health authorities or health workers who have been using antibody tests may need to find another testing tool or test people twice to get better results, CDC said. The agency estimates that the current prevalence of coronavirus antibodies is low, only between 5 percent to 25 percent, even in heavily affected countries.

Antibody Tests Errors And Confidence

Since there is a chance that antibody tests may show that a person had COVID-19 despite not having it, health experts fear that the error could contribute to the spread of the virus. That is because it would make people believe that they are already immune to the disease, leading to changes in their behavior in public. 

"It cannot be assumed that individuals with truly positive antibody test results are protected from future infection," the CDC said. "Serologic testing should not be used to determine immune status in individuals until the presence, durability and duration of immunity is established."

The CDC is not the first to warn health authorities and experts about the accuracy of antibody tests. The Food and Drug Administration (FDA) and researchers at the University of Minnesota previously cautioned against using the tool to manage COVID-19 cases and make policy decisions, according to CNN

COVID-19 antibody test The Centers for Disease Control and Prevention (CDC) issued a guidance saying antibody tests may not always provide accurate results to identify COVID-19 infections. Pixabay

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