Coronavirus Information: How Accurate Are Antibody Tests?

The public can now easily access antibody tests for COVID-19 since companies received approval from the federal government to market their products. However, health experts warned the approach to determine past coronavirus infections still has limitations and that accuracy can be a problem.

Medical testing companies like Quest Diagnostics and LabCorp now have antibody tests available online or in clinics. The increased access comes after the Food and Drug Administration (FDA) allowed hundreds of the tests to enter the market amid the COVID-19 pandemic.  

However, health experts questioned the decision because scientists have yet to fully understand the accuracy of antibody tests. Even the Centers for Disease Control and Prevention (CDC) announced early in June that antibody tests are not yet reliable enough.

Many questions still surround the link between the novel coronavirus and antibodies. Researchers have yet to confirm if antibodies formed after recovering from COVID-19 can really provide immunity, how long protection might last and the amounts of antibodies needed to prevent reinfection. 

“We’ve already measured the antibodies in many people, so we know that an immune response is there,” Michael Mina, assistant professor of epidemiology at the Harvard T.H. Chan School of Public Health, said as quoted by WebMD. “We just have to get better, more nuanced information about what those responses mean and how to interpret them.” 

Problems With Antibody Tests

Since states have been slowly reopening and allowing businesses to resume operations, some companies are using antibody tests to determine which employees may return to work. However, commercial antibody tests that claimed 100 percent accuracy are still likely to give false-positives, according to Andrew Azman, assistant scientist in the Department of Epidemiology at Johns Hopkins University Bloomberg School of Public Health.

Azman and his colleagues warned that relying on antibody tests may give people a sense of false security. That may increase the risk of new coronavirus infections because they might stop following safety measures. 

“Until we have more evidence, serological tests alone should not be used to make decisions such as when staff can return to work, the need for personal protective equipment or the need to discontinue social distancing measures,” according to a recent joint statement from the Association of Public Health Laboratories (APHL) and the Council of State and Territorial Epidemiologists (CSTE).

There are dozens of studies ongoing in the U.S. and other countries to further understand how coronavirus antibodies work to give immunity. Some of the studies involve following people who recently recovered from COVID-19 to see how their body would respond to possible reinfections. 

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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