Pros and cons of COVID-19 antibody testing

How accurate are the coronavirus antibody tests?

Pros and cons of COVID-19 antibody testing
The antibody test is a blood test that shows if a person might have previously had COVID-19. (Source: WIS)

MEMPHIS, Tenn. (WMC) - Local doctors are offering antibody testing allowing people to learn if they’ve previously had coronavirus, but how accurate are they?

Antibody tests can determine if someone previously contracted COVID-19 weeks ago, by looking for antibodies that were produced when the body was fighting the infection. They are not used to testing people who actively have the virus.

Dr. Andranette Flemming at Women’s Health Care Associates is one of several doctors in the Mid-South making tests available to the public.

“We actually do the blood work right here in the office,” said Fleming.

Fleming then sends the $60 tests to a lab. The tests she uses come from Abbott Labs, one of the few antibody tests approved by the FDA.

“In about five days, sometimes sooner I will call you with your results,” said Fleming.

Monday the FDA cracked down on the nearly 200 commercial antibody tests that have hit the market, citing that some test kits are fraudulent and show inaccurate results.

Infectious disease expert Dr. Steve Threlkeld says it’s crucial that the tests are accurate.

“If they’re not terribly specific - that is to say, if they call some people positive that really aren’t positive - then all of a sudden you have a whole new problem on your hands,” he said. “You have a group of people that you’ve told they’ve had the infection, they’re over it and they’re good. They can sometimes have a false sense of security.”

Accurate antibody testing allows researchers to gather data on who has gotten the virus, including those who've showed no symptoms of being sick. It may even help develop a treatment to fight the virus.

But experts have not been able to determine if someone is immune once they’ve had it. Threlkeld says a positive antibody test may not necessarily mean you’re safe from ever getting the virus again.

“In any one person, if you come to me and say ‘I have a positive antibody test’, I may say that’s great,” said Threlkeld. “You may be able to donate plasma soon, but you still need to be careful because we don’t have certainty of how long those antibodies protect you yet. So we still need to treat ourselves as if we’re not positive just to be on the safe side.”

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