The FDA granted its first emergency authorization for a rapid antibody blood test for COVID-19, developed by Cellex, allowing people to gauge a person’s immune response to the novel coronavirus.
The serological test—which uses a few drops of blood drawn from a vein and dropped into a device containing a small strip, similar to a combination of a blood glucose test and a home pregnancy exam—detects two different types of antibodies produced by the body to fight off the infection. Available by prescription, this can be used to determine whether a person has been previously infected and possibly recovered.
It is distinctly different from the nearly two dozen diagnostic tests the FDA has officially authorized so far, which focus on finding active infections by sequencing the genetic material of the virus.
Cellex—with offices in Shenzhen and Suzhou in China and in North Carolina’s Research Triangle Park—said its CE marked test should deliver a reading in 15 to 20 minutes. However, the test may not work in the first few days of an infection, before enough antibodies are produced as part of the immune system’s response.
Previously, the agency told serological test developers that it would not object to the unreviewed use of these rapid blood tests, describing them as less sophisticated compared to the high-throughput sequencing diagnostics in use nationwide. Companies are required to validate their work and include instructions saying their test must not be used as the sole method of testing a patient for COVID-19, as does Cellex.
Currently, the FDA maintains a public list of nearly 50 other serological test manufacturers, the majority based in China, that have notified the agency of their plans to distribute their products in the U.S. without seeking an Emergency Use Authorization.
That list includes BioMedomics, which has announced plans with medtech giant BD and medical supply company Henry Schein to distribute their fingerprick-based version on a large scale. It does not include Hangzhou, China-based Safecare Bio-Tech, maker of tests set to be distributed by BodySphere, which earlier this week incorrectly claimed to have received an FDA authorization.
Editor’s note: This story has been corrected to show that Cellex’s test takes blood via venipuncture, not through a finger stick.