CDC Director Robert Redfield confers with Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, during a Jan. 28 press conference in Washington, D.C., on the public health response to the coronavirus.

WASHINGTON, DC – JANUARY 28: Centers for Disease Control and Prevention Director Robert Redfield whispers to National Center for Immunization and Respiratory Diseases Director Nancy Messonnier during a press conference today at the Department of Health and Human Services on the coordinated public health response to the 2019 coronavirus (2019-nCoV) on January 28, 2020 in Washington, DC. The virus, which originated in Wuhan, China, has infected 4,500 people and killed at least 109, mostly in China. Currently 110 people are being evaluated in the United States for infection, with five confirmed cases. (Photo by Samuel Corum/Getty Images)