The virus behind the pandemic

The novel coronavirus is novel in a number of ways. It’s disturbingly easy to spread, often coming from people with no symptoms. It seems especially fatal to older men. And some countries that would seem in the direct path of the virus have few cases. What else do we know and still not know about the virus? Gabriel Leung is an infectious disease epidemiologist and the dean of medicine at the University of Hong Kong. He’s on the forefront of understanding the coronavirus. Marco Werman speaks with Leung about his current understanding of the virus and what still puzzles him.