These officials have emphasized that the virus is spread mainly by people who are already showing symptoms, such as fever, cough or difficulty breathing. For weeks, federal officials have emphasized that asymptomatic transmission can happen, but have said that it's not a significant factor in the spread of the virus. On March 1 on ABC's This Week , US Secretary of Health and Human Services Alex Azar told host George Stephanopoulos that asymptomatic spread is "not the major driver" of the spread of the new coronavirus. But during a press briefing at the White House on Saturday, the administration's coronavirus response coordinator, Dr. Deborah Birx, seemed to strike a somewhat different note on asymptomatic transmission. Others agree that people without serious symptoms play a substantial role in the spread of the new coronavirus.

Source: CNN March 14, 2020 19:30 UTC