FDA Has Authorized COVID-19 Test Based on Antibodies
The Food and Drug Administration has granted its first authorization for COVID-19 testing that uses antibodies present in human blood, instead of swabs from the nose or throat, reports The Verge. There are limits to the effectivity of this test, but it will significantly help in the response to the coronavirus pandemic.
Antibody tests approved for COVID-19
Called a serology test, this new option will allow the detection of past coronavirus infections but will be less efficient at detecting new ones, according to CNN. The test is manufactured by a biotechnology company called Cellex. Health care providers draw blood from veins in a patient to run the test, and it only works in certified labs — not a doctor's office. Results from the test take roughly 15 to 20 minutes.
"JUST IN: @US_FDA announces approval of #COVID19 antibody test in @CBSNewsRadio interview," read a tweet from CBS News Radio's Twitter account.
Upon initial infection with a virus, the host's immune system kicks into overdrive, producing antibodies uniquely attuned to fight the specific virus. This is why doctors can check for coronavirus infection. But there's a flaw intrinsic in this method — the body doesn't produce these antibodies immediately, and might not even appear until an infection has run its full course.
This means that while antibody tests can tell doctors if someone has had the novel coronavirus, false negatives — where a test correctly shows no coronavirus-specific antibodies, but the virus is nevertheless active — make antibody tests less effective and useful than other methods.
Fighting the outbreak via antibodies outweighs the risks
Regardless, the FDA authorization implies that the agency thinks the benefits of making the test available outweigh the risks of not having the option. "It is reasonable to believe that your product may be effective in diagnosing COVID-19," said the agency in the letter that authorized the antibody-based test, posted on the FDA website.
This isn't to say companies couldn't distribute or use antibody tests before the authorization — they did. However, companies using the antibody test for COVID-19 were until Thursday not allowed to claim the test could diagnose the illness.
A main benefit of the disease is the ability to know whether those who have contracted and survived the virus showed symptoms, and, as a consequence, whether their immunity is strong enough to permit normal movement in public life, including work.
The tests will also help public health officials know the extent of the COVID-19 coronavirus' spread in the population. As of writing, dozens of companies are working to develop antibody tests, in addition to researchers at the Centers for Disease Control and Prevention.