New blood tests for antibodies could show true scale of coronavirus pandemic

How many COVID-19 cases have gone undetected? And are those who had mild cases of the disease—perhaps so mild they dismissed it as a cold or allergies—immune to new infections? If so, they could slow the spread of the burgeoning pandemic Labs and companies around the world have raced to develop antibody tests, and a few have been used in small studies and received commercial approval, including several from China But so far, large-scale data from such tests—for example showing what fraction of people in the hard-hit city of Wuhan, China, might now be immune—is still lacking or at least not public Scientists hope that will soon change as more tests become available