Understanding the Virus and Its Unanswered Questions: QuickTake

It’s taken scientists time to understand that the novel coronavirus that emerged in late 2019 in central China behaves differently than similar pathogens, producing missteps in the response. The list of known symptoms of Covid-19, the disease it causes, also has grown, complicating efforts to diagnose and treat it. And the virus has yet to give up all its mysteries, creating uncertainty about when the pandemic might end.