The South Plains Public Health District said there have been 15 confirmed measles cases in Gaines County. While a majority of the cases are of school-aged children, there are now a few adult cases. The South Plains Public Health District said all of the cases were unvaccinated.

Fifteen measles cases — mostly in school-aged children — have been confirmed in a small county in West Texas with one of the highest rates of vaccine exemptions in the state. Some of the cases appear to be connected to private religious schools in the district, said Holbrooks, who cautioned that the investigation is ongoing.

The outbreak in Gaines County, with a population of about 22,000, has grown since two cases were reported in January. All those who contracted measles were unvaccinated, health officials said.

On January 30, officials reported two measles cases in unvaccinated, school-age children in Gaines County, which sits at the border of New Mexico and is around 90 miles southwest of Lubbock, Texas. Both children were hospitalized in Lubbock and had been discharged.

As another community in Texas confirms positive measles cases, here's what to know about symptoms of the highly contagious virus that impacts children.