Measles outbreaks in the United States, including the latest one linked to visitors to Disneyland, highlights the global need to eliminate measles. When the virus lands in the U.S., usually due to Americans traveling parts of the world where measles is a huge problem, measles spreads to vulnerable, unimmunized pockets like those found in at least 7 U.S. states in the latest outbreak tied to Disneyland.

More in this NPR story.