Six months of coronavirus: the mysteries scientists are still racing to solve

By Ewen Callaway, Heidi Ledford, & Smriti Mallapaty In late December 2019, reports emerged of a mysterious pneumonia in Wuhan, China, a city of 11 million people in the southeastern province of Hubei. The cause, Chinese scientists quickly determined, was a new coronavirus distantly related to the SARS virus that had emerged in China in …