A child’s death this past week in Texas is the first U.S. death from measles, a highly contagious but preventable respiratory disease since 2015, according to the U.S. Centers for Disease

People considering becoming pregnant should get their measles, chicken pox and rubella antibodies checked before conception.

Measles is one of the most contagious viruses known to humans, experts say. Measles has been spreading across the U.S. for the last several weeks, sickening people in at least nine states amid a growing outbreak in western Texas.