A fast-growing measles outbreak in West Texas has nearly doubled in just one week, now totaling 90 cases across seven counties and spreading to New Mexico. Earlier this week, the Texas Department of State Health Services confirmed 49 cases in five counties.

Texas' measles outbreak is up to 90 cases. Here's what you need to know about the virus, vaccination and boosters.

The U.S. Centers for Disease Control and Prevention on Friday reported that measles cases so far this year had jumped to 93 from 14 a week ago, mainly driven by an outbreak in Texas. The Texas Department of State Health Services said last week that more cases of the highly contagious disease were likely to surface due to an outbreak in Gaines County.