The number of new coronavirus cases across the country are down, as mask rules are being more stringently enforced, school districts are closing en masse, and doctors begin using a new plasma treatment. But a Hong Kong man is the first person known to be infected with the coronavirus twice, indicating that antibodies are either short-lived or are not a protection against the disease. Dr. Jason Kindrachuk, an assistant professor of viral pathogenesis at the University of Manitoba and Canada Research Chair in molecular pathogenesis of emerging and reemerging viruses, joins the show.