Vaccinated or not, we’re on the brink of a measles epidemic

Measles is making a comeback. Ongoing outbreaks in Pennsylvania, South Carolina, Texas, and Utah have documented hundreds of cases, mostly among unvaccinated people. And while local and federal politicians debate the definitions and impact of those measles-associated deaths, health experts worry that we're overlooking the real problem: the threat of a full-scale epidemic. Today, we talk to one of those experts – epidemiologist Michael Mina – to figure out who's most at risk, and whether there's any way for us to turn this epidemic around.