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 2003, before spreading globally and killing nearly 800 people.
Six months and more than ten million confirmed cases later, the COVID-19 pandemic has become the worst public-health crisis in a century. More than 500,000 people have died worldwide. It has also catalysed a research revolution, as scientists, doctors and other scholars have worked at breakneck speed to understand COVID-19 and the virus that causes it: SARS-CoV-2.
How deadly is the coronavirus? Scientists are close to an answer
They have learnt how the virus enters and hijacks cells, how some people fight it off and how it eventually kills others. They have identified drugs that benefit the sickest patients, and many more potential treatments are in the works. They have developed nearly 200 potential vaccines — the first of which could be proved effective by the end of the year.