At least 124 cases of measles have been identified in Texas since late January, mostly among children and teenagers who are either unvaccinated or whose vaccination status is unknown, officials say.

Texas officials on Wednesday announced the first measles death in the state's ongoing outbreak of the highly contagious disease. The death, of a school-age child, is the first measles death in the U.S. since 2015, according to the Centers for Disease Control and Prevention.