A measles outbreak that has caused the deaths of two school-aged children has now surpassed more than 500 cases across Texas, according to health officials. The latest update from the Texas Department of State Health Services shows that 505 people have been infected with measles since the outbreak began in late January in the South Plains region.

About 500 Texans, mostly young unvaccinated children, have contracted the disease. The U.S. health secretary was in West Texas to visit the family.