There’s been increasing anxiety over the last several weeks about an outbreak of measles in Texas and New Mexico. Public health officials in the Southwest are sounding the alarm — including Will Humble,

Arizona hasn’t had any measles cases yet this year, but a local medical expert thinks “it’s just a matter of time” as vaccination rates decline.

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. Several people have been hospitalized and at least one unvaccinated school-aged child in Texas has died,