The US has reported more than 200 cases of measles this year, mostly in Texas and mostly affecting unvaccinated people. Public health experts in the US and worldwide are concerned about the spread of this highly contagious disease. Host Marco Werman speaks with Dr. Peter Hotez at Baylor College of Medicine about the outbreaks of measles in other countries, its spread across borders and the correlation between measles outbreaks and local rates of vaccination.