Travel bans meant to stop the coronavirus from getting to the US from China and Europe came too late, according to a new analysis of cases from the US Centers for Disease Control and Prevention. The US restricted travel from China on February 2 and from Europe on March 13, but by March 8, Covid-19 was already circulating among the community in New York City and, by March 15, community transmission of the virus was already widespread, the analysis found.However,what was circulating most closely matched the strain of the virus circulating in Europe, not China.