After a pediatric patient in West Texas died of measles complications, hospital officials are urging the community to take the outbreak seriously, and to educate themselves about the virus and vaccination.

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

The measles outbreak in Texas has now turned deadly. Texas and federal health officials have just reported the first deaths attributed to the still-growing outbreak, which has sickened over a hundred people.