According to the article, China has instituted "one of the greatest infectious-disease containment efforts the world has ever seen":

By contrast, three weeks after the first known case of the disease now known as COVID-19, China had notified the WHO of a spike in cases of a pneumonia-like disease. Two weeks after that, the coronavirus had been isolated, genetically sequenced, and a diagnostic test developed, giving China the tools it needed to launch one of the greatest infectious-disease containment efforts the world has ever seen.

If "one of the greatest infectious-disease containment efforts the world has ever seen" has not resulted in contaiment and the virus has continued spreading, as your comment suggests, we will soon find out -and in a very unpleasant manner.

Or, to not put too fine a point on it: in that case we're in deep shit.