While it might be impossible to figure out who is going to become sick with novel coronavirus, some public health experts believe the more critical question may be who has already been exposed. In Telluride, Colorado, last week, one biotech company put that idea to work. United Biomedical is now working with San Miguel County, which includes the famous Rocky Mountain ski destination, to test all 8,000 residents for COVID-19 antibodies -- making it the first community in the country to do widespread antibody testing. The idea, officials said, is to learn from an individual’s blood whether there is evidence...