The Food and Drug Administration has revoked its emergency green light for a fingerstick COVID-19 antibody blood test developed by Hauppauge-based Chembio Diagnostic Systems.

The FDA cited new concerns over the test's accuracy.

"Tests need to be extraordinarily sensitive and specific in order to have what we call a positive or predictor value, meaning if you test positive or you test negative, what does it actually mean?" says Northwell Health Senior Vice President Dr. David Battinelli. "So it was simply known after a number of tests were done that it did not meet those criteria and hence appropriately, in my opinion, withdrawn."

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Since late April, the FDA has been working with the National Institutes of Health, the Centers for Disease Control and Prevention and the National Cancer Institute to double-check the performance of antibody tests.

In its revocation letter to Chembio, the FDA wrote, "New information from three evaluations performed since authorization of the device demonstrates its performance may be both inconsistent and lower than that described in your original submission."

The FDA said an independent evaluation by the NCI showed the tests generated a "higher-than-expected rate of false results" and that the independent tests "suggest significant performance concerns with your device, which may put patients at unreasonable risk of harm due to inaccurate results."

"If somebody gets a false positive it looks like they have antibodies, even if we know you have antibodies, we're not positive what that means, but the assumption is you have some degree of immunity," says Battinelli. "So if somebody makes that assumption, even though we're not clear on what that is yet and believes they have some degree of immunity when they don't have immunity, that obviously puts them at risk."

Chembio's shares tumbled more than 60% after the FDA's decisions. The company did not return requests for comment.