THE covid-19 virus is humanity’s newest foe, with the potential to prematurely end millions of lives. To control this new coronavirus , we need to understand it. Labs around the world are now working around the clock in a bid to know their enemy.

Three crucial questions are occupying virologists. What makes the new virus so good at infecting people? How does it reproduce so quickly once it is inside us? And why doesn’t the virus cause symptoms straight away, allowing it to spread undetected? The answers will suggest ways to treat …