The outbreak — which includes 124 people — has led to the country's first measles death since 2015, as vaccination rates continue to decline in the U.S.

The first person known to have died from measles in the U.S. in a decade was announced by health officials on Wednesday and described as a "school-aged child" who perished in a children's hospital in West Texas,

It's the first measles death in the U.S. since 2015. More than 130 people in west Texas and New Mexico have been sickened in the outbreak so far.