The number of measles cases has risen to 309 as the historical outbreak continues to rage on in West Texas and three new counties report infections, according to state officials on Friday. Of those, 40 patients are hospitalized.

But there's a silver lining, officials say: More people have received a measles, mumps, and rubella vaccination this year in Texas and New Mexico, which also has an outbreak, compared to last year -- even if it's not as high as they would like. And pharmacies across the U.S., especially in Texas, are seeing more demand for MMR shots.

The Texas health department reported 309 measles cases in the state on Friday, an increase of 30 cases from its previous count. Cases in Gaines county, the center of the outbreak, rose to 211 from 191 as of March 18,