A child has died of measles in Texas, officials said — the first death from the highly contagious disease the United States has seen in a decade. The school-age child was not vaccinated, according to the Texas Department of State Health Services.

State and local health officials are urging individuals to receive MMR vaccine as Texas reaches 124 cases this week. Here is what we know.

Texas reported 90 cases this week, while New Mexico reported nine. A majority of the cases have been in a Texas county where vaccination rates have lagged behind the rest of the state.