Company says it has a better way to detect past COVID infections

(Journalist)
– Scientists believe millions of people have been infected with the coronavirus and have recovered without ever knowing for sure if they have it. Antibody tests have been used to spot past infections, but researchers say a new test to detect immune cells called ‘T cells’ could be much more effective New York Times reports. Seattle-based company Adaptive Biotechnologies says that in research using samples from Vo, Italy, where the entire city was tested in March, its “T-Detect” test was able to correctly identify 97% of those who had tested positive, while a commercial antibody test only identified 77%. Experts say T cells are a more reliable indicator of past infection than antibodies, which decline after the body fights the infection and may be undetectable after a few months.

“The source of antibodies – the factory that makes them – dies within months,” while T cells tend to stay around much longer, Akiko Iwasaki, an immunologist at the Yale School of Medicine, told CNN. “For other viruses, they have been shown to persist for years. For this virus, we don’t know how long they last, but we would expect at least a few years, ”she says. T cells for individual viruses are much more difficult to detect than antibodies, although Adaptive Biotechnologies, which was developing a test for Lyme disease when the pandemic struck, says its technology has been able to successfully detect evidence of infection by identifying proteins on the surface of cells called T-cell receptors. The company hopes to launch the test commercially by the end of the month. (Read more stories about coronaviruses.)