Virologist answers key questions on deadly virus

As of March 23, there were 336,000 confirmed cases of Covid-19 in the world, with more than 250,000 cases outside China. Despite these numbers, much is still misunderstood or unknown about the virus, which has brought regions of the globe to a standstill and placed huge pressure on the global economy.

Even what we do know – that elderly people are more at risk, that this is a new virus but resembles other known epidemics, that it is highly infectious – requires more explanation.