Intervening in Zika virus

11:17 AM ET Mon, 1 Feb 2016

A number of pregnant women are infected with the Zika virus, carrying babies at risk of brain defects, in South America. Infectious disease expert Dr. William Schaffner of Vanderbilt University, discusses the potential spread to the U.S., saying the Zika virus could be "a more difficult problem" than Dengue fever and the Chikungunya virus.