Antibody tests, which are different than coronavirus tests, are being issued to see who has experienced the virus and whether those people have developed an immunity to it that could help mitigate the current effects of COVID-19 around the world. These tests started becoming available to people across the country in early April after the FDA approved a new program under an Emergency Use Authorisation. But now, as many hope that these tests will allow for some kind of immunity from all measures to fight the virus, many wonder how accurate they really are.
According to the New York Times, experts have been working nonstop for the past few weeks to confirm what the Food and Drug Administration (FDA) mostly has not yet done. Scientists have been trying to verify whether 14 coronavirus antibody tests that are currently on the market actually deliver accurate results, after the FDA pushed through many antibody tests on the market that they never reviewed.
And according to current research results, only three out of 14 tests on the market truly deliver consistently reliable results. “There are multiple tests that look reasonable and promising,” said Dr. Alexander Marson, an immunologist at the University of California, San Francisco, and one of the project’s leaders. “That’s some reason for optimism.”
Because of the study results, it’s unclear how accurate antibody test results are, with even the best three versions of this exam resulting in some flaws. Researchers found that only one of the tests they tried never delivered a false positive — or a test that mistakenly showed signs of antibodies in people who didn’t actually have them. The two other tests they investigated didn’t deliver false-positive results approximately 99 percent of the time, but still showed a few incorrect cases. And while doctors like Marson might see hope in some of the tests, others disagree.
“Those numbers are just unacceptable,” Scott Hensley, a microbiologist at the University of Pennsylvania, told the New York Times, adding, “The tone of the paper is, ‘Look how good the tests are.’ But I look at these data, and I don’t really see that. If your kit has a 3 percent false-positive, how do you interpret that? It’s basically impossible. If your kit has 14 percent false positive, it’s useless.” So if even the three most accurate tests still only proved to detect antibodies 90 percent of the time in people who have been infected, what does that mean for the overall accuracy of antibody tests?
Experts say that ensuring that tests don’t give false-positives is extremely important to everyone’s overall health — if someone receives a false positive and believes that they’re immune to COVID-19 when they aren’t, they could be putting themselves in danger by abandoning necessary measures like social distancing or isolating.
That means that even if you’re able to score an antibody test and test positive for having antibodies associated with COVID-19, it’s likely still best to lay low, as scientists suggest — especially with new symptoms being discovered.
The more that scientists and hopefully the FDA conduct rigorous testing to make sure antibody tests get to a point of 100 percent accuracy, the sooner it will be safe to be able to completely trust the test results. The accuracy of the tests will vary based on what test you're taking, and many factors, scientists say, but the most significant measure in this testing program is ensuring accuracy.