H5N1 avian flu viruses (seen in gold) grow inside canine kidney cells (seen in green). Cynthia Goldsmith/CDC hide caption

itoggle caption Cynthia Goldsmith/CDC

Connor Perruccello-McClellan, a senior at Providence Country Day School in Rhode Island, has been vaccinated against HPV, something less than 1 percent of U.S. males can say. Richard Knox/NPR hide caption

itoggle caption Richard Knox/NPR

Ohio State Highway Patrol troopers talk with motorists at a sobriety checkpoint in 2006, the year CDC says drunk driving peaked.

David Kohl/AP hide caption

itoggle caption David Kohl/AP

Laurence Fishburne as Dr. Ellis Cheever and Kate Winslet as Dr. Erin Mears in the thriller Contagion. Winslet's character was modeled on CDC epidemiologist Dr. Anne Schuchat. Claudette Barius/Warner Bro. Pictures hide caption

itoggle caption Claudette Barius/Warner Bro. Pictures