The ability to trace the contacts of people who’ve been infected with the coronavirus, even those without symptoms, is critical in the fight against the pandemic.
Antibody tests have emerged as a tool in that fight, but during an interview with WTOP, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, said they can’t do it all.
Antibody tests look for the presence of antibodies produced in response to the coronavirus and can determine whether someone has been infected, even if the virus isn’t still in the body. That means asymptomatic carriers who never received a traditional test can still find out if they were infected with COVID-19 by taking an antibody test.
At the start of the coronavirus outbreak in China, Fauci told WTOP early indications were that only a very small percentage of those infected were asymptomatic — around 5%.
“Now that we get much more experience, that number looks like it’s more between 25% and 50%,” Fauci said.
“It makes it that much more difficult to track down contacts as well, for example, and to identify people easily by their symptoms. It just adds an additional dimension of difficulty in addressing the outbreak the way you would like to.”
The D.C. region saw massive protests and accelerated reopening over the weekend, and as people start to interact more frequently, the need for effective contact tracing grows.
So everyone just needs to take an antibody test, right?
How much can antibody tests do?
Fauci said there are plenty of caveats when it comes to the tests and the antibodies themselves.
Many tests lack accuracy, but the Food and Drug Administration has a list of tests that have been granted emergency use authorization with published performance results.
The National Cancer Institute is assisting the FDA in evaluating antibody tests.
“If you are taking a test and it’s a validated test, then you can rely on its accuracy, but you can’t ask the test to do too much,” Fauci told WTOP.
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That’s because not everyone who gets infected and recovers gets a high level of antibody, according to Fauci.
In some cases, recovered patients don’t have any measurable antibody at all.
“That doesn’t happen often, but often enough to kind of confuse the picture,” he said.
Fauci said the relationship between the level of antibody and protection against the virus still isn’t clear as well, and experts aren’t sure how long the antibodies stay in the body.
While it seems like there are more questions surrounding antibody testing than answers, Fauci said a validated test can still give valuable information.
“In the big picture, it certainly is compatible with and likely that if you are antibody positive you’ve been infected and you’re protected, at least for a finite period of time. But the details of that are still evolving,” Fauci said.
Moving toward a vaccine
As encouraging health metrics allowed parts of Maryland and Virginia to start reopening, the D.C. area lagged behind, and Fauci told WTOP the numbers were concerning.
REOPENING PLANS AROUND THE REGION:
“I was a little concerned that it took a little longer than I would’ve liked to see the plateauing and the beginning of diminution in the Washington, D.C., area,” Fauci said. “We’re starting to see that now and we appear to be turning a corner.”
But that turning point came as mass crowds were filling D.C. streets in protest. Saturday marked the largest day of protests in the District since the May 25 death of George Floyd in Minneapolis police custody.
Fauci called the protests “the perfect setup” for spreading the virus but added that the reason for the demonstrations is valid and weighing the risk of the gatherings is a “delicate balance.”
Protesting or not, Fauci urged people to continue to practice preventative health measures, such as social distancing and wearing masks, until a vaccine is available.
“Right now we’re trying to so-call reopen America and get back to some normalization,” Fauci said. “Make sure we do it in a way that’s prudent and careful and I think we will be fine.”