Coronavirus In Minnesota: What Can COVID-19 Antibody Tests Tell Us?
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MINNEAPOLIS (WCCO) -- Experts think antibody testing could be key in the long-term fight against COVID-19. Those are the blood tests that can determine, after the fact, if someone was infected with the virus.
Minnesota Gov. Tim Walz said Monday the testing is promising, but will not be a panacea.
"I think we shouldn't kid people to think that massive testing makes everything go back to normal, but it does move us to a better place," Walz said.
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That said, questions remain about what the antibody test can and can't tell individuals and decision makers, according to Dr. Elitza Theel, director of the Infectious Diseases Serology Laboratory at the Mayo Clinic
"I think they'll be an appropriate tool," Theel said. "I don't think we can use them as a silver bullet."
When Mayo decided it would do COVID-19 antibody testing, it ran its own tests of five of the antibody tests currently on the commercial market. Ultimately, Dr. Theel says Mayo settled on one that she's comfortable with when it comes to accuracy.
"That being said, there is no perfect test," Theel said. "There will be a chance of a false-negative or a false-positive result."
Her laboratory tested 350 samples. Of the samples they knew were positive – which had been collected from COVID-19 hospitalized patients who had previously tested positive -- antibodies appeared in 100% of the samples. Of the samples they knew were negative – which had been collected in 2018 before the virus appeared -- 1% of those showed up positive.
"Using testing that's being performed in accredited laboratories is the best way to ensure you're getting accurate results," Theel said
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Over the past few weeks, there have been questions about the accuracy of some antibody tests on the market, according to Dr. Jon LaPook, a recent guest on CBS This Morning.
"At the very beginning there wasn't that much control. A lot of them, dozens and dozens, got rolled out," LaPook said. "And we know that there were false positives and false negatives."
At this point, the United States Food and Drug Administration hasn't approved any COVID-19 antibody tests, but it has given emergency authorization to four companies. More than 100 others have validated their tests and sent that information to the FDA. That includes the company behind Mayo's test.
For over a week, the Mayo Clinic said it's had the capability to perform 10,000 COVID-19 antibody tests per day.
"Nothing is stopping us, but I think the bigger question that we have to answer is how to appropriately use these tests, and what do these results mean," Theel said.
She said these tests can tell whether someone has been infected with COVID-19 at some point.
"What we're still learning about is whether that antibody actually means that is patient is protected from the infection," Theel said.
She said other small studies have suggested some form of short-term immunity.
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The University of Minnesota has created its own COVID-19 antibody test and hopes to be screening 1,000 people a day by the end of next week, according to Amy Karger, director of antibody testing at the U.
"There's definitely information to be drawn from these tests," Karger said. "None of these tests were built to be definitive."
The Minnesota Department of Health says these tests should not be used as the sole basis right now to diagnose or exclude infection or immunity.
Rather, experts said it's just one piece of beating COVID-19. Other kinds of testing and tracing will also be required.
"I think the drawbacks of antibody testing need to be taken into account with the great potential promise," Gov. Walz said.
