A child in West Texas has died of measles, state health officials said on Wednesday, the first reported U.S. death from the highly contagious disease in a decade, as a Texas outbreak has grown from a handful of cases to more than 130 across two states.

The childhood measles-mumps-rubella vaccine will usually protect you against the measles for your entire life.

Here’s what to know about the outbreak after the first U.S. death since 2015 from the highly contagious—but preventable—respiratory disease.