(CNN) The world has come to depend on antibody tests to check whether someone's already had Covid-19, but a study in the town where the virus first spread in Italy shows that these tests are not completely reliable. A different test -- one that looks for an immune cell, called a T cell -- was more effective, according to the study. It's well known that antibodies wane, but T cells have immunological memory," said Dr. Peter Hotez, an infectious disease specialist at Baylor College of Medicine. In the study, researchers in Italy, the United Kingdom and the United States studied people in Vo, Italy, to learn more about testing accuracy. They conducted blood tests on 70 people who had had confirmed cases of coronavirus about two months earlier.

Source: CNN November 11, 2020 00:33 UTC