By Marie Rosenthal, MS

As COVID-19 spreads across the United States—more than 35 states have reported at least one case—Americans want to know what they should do to protect themselves.

Nancy Messonnier, MD, the director of the CDC’s National Center for Immunization and Respiratory Diseases, spent some time with reporters today to talk about risk, so that people can better determine how they should respond.

“This virus is capable of spreading easily and sustainably from