WASHINGTON, DC - JULY 13: Center for Disease Control Director Tom Frieden participates in a discussion about 'Zika, the Olympics, and Global Health Security: A Marathon Against a Microbe' at New America July 13, 2016 in Washington, DC. Frieden said that the CDC's response to the Zika virus has been the most complex he has overseen, with more than 1000 employees working across many departments. 'Congress did the right thing with Ebola,' Frieden said. 'I hope they do the same with Zika funding as well. But speed is of the essence.' (Photo by Chip Somodevilla/Getty Images)