The U.S. Food and Drug administration granted emergency approval for another two coronavirus blood tests, both developed to determine who has already recovered from the fast-spreading illness.
The antibody tests are not necessarily diagnostic but rather detect certain proteins in the immune system by way of a blood sample.
The presence of antibodies in the blood indicates an exposure to the virus and that the human body has responded to it. While they do suggest a person has recovered from COVID-19, it’s unclear whether that means they will have long-term immunity from the illness.
As of Thursday, there were three tests authorized for use by the FDA, according to CNN. The agency noted that a negative result does not necessarily mean you haven’t been infected and warned of possible false negatives.
“A negative result may occur if you are tested early in your illness and your body hasn’t had time to produce antibodies to the infection,” according to an FDA fact sheet.
But the risks associated with incorrect results outweigh the risks of not doing the tests at all. Experts hope they will prove useful in understanding how widespread the virus is given many cases have mild or no symptoms at all.
The newly authorized tests, which are limited to use in laboratories, were developed by Chembio Diagnostic Systems and Ortho Clinical Diagnostics, which is located in Rochester, N.Y.
As of Thursday, more than 2 million people worldwide have been infected with the virus. Of those, nearly 140,000 have succumbed to the illness, according to the most recent data from Johns Hopkins University.
