The latest genetic, epidemiological and computational research suggests that Americans were transmitting the virus within the country as early as January. Airports in San Francisco, Los Angeles and at New York’s JFK were the only ones where there was screening. A strain of the virus likely imported from France spread among attendees of the Biogen conference in Boston on Feb. 26-27. A lack of testing meant people didn’t realize the virus was spreading. They then returned to 18 states and the District of Columbia, the U.S. Centers for Disease Control and Prevention said.

Source: Wall Street Journal October 09, 2020 21:11 UTC