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White House coronavirus task force member Dr. Anthony Fauci is urging caution about relying on coronavirus antibody tests to determine whether someone who has recovered from the illness is immune.

Fauci said on “Good Morning America” that “we still have a way to go” with antibody, or serology, tests, which check for proteins in the immune system through a blood sample.

The presence of proteins means a person was exposed to the coronavirus and developed antibodies against it, which may mean they have at least some immunity.

Health officials suggested that tests could be used as a way to help determine when to reopen communities.

“The problem is that these are tests that need to be validated and calibrated, and many of the tests out there don’t do that. So even though you hear about companies flooding the market with these antibody tests, a lot of them are not validated,” Fauci said.

“There’s an assumption — a reasonable assumption — that when you have an antibody that you are protected against reinfection, but that has not been proven for this particular virus. It’s true for other viruses,” he said.

The director of the National Institute of Allergy and Infectious Diseases added that “we don’t know how long that protection, if it exists, lasts. Is it one month? Three months? Six months? A year?

“So the assumption that with the tests that are out there, if you have an antibody positivity, you’re good to go — unless that test has been validated and you can show there’s a correlation between the antibody and protection, it is an assumption to say that this is something that we can work with,” Fauci said.

“We still have a way to go with them,” he added.

Meanwhile, Fauci also said there would be no real economic recovery if the US doesn’t get coronavirus “under control.”

“Clearly, this is something that is hurting from the standpoint of economics, from the standpoint of things that have nothing to do with the virus,” Fauci said when asked about protests that have erupted across the US amid shelter-in-place orders.

“Unless we get the virus under control, the real recovery economically is not going to happen,” he told ABC’s George Stephanopoulos.

“If you jump the gun and go into a situation where you have a big spike, you’re going to set yourself back,” Fauci continued. “So as painful as it is to go by the careful guidelines of gradually phasing into a reopening, it’s going to backfire.”