Measles cases in Texas and New Mexico rose to 351 on Friday, the health departments of the states said, an increase of 34 infections over the last three days as the United States deals with one of the largest measles outbreaks in the past decade.

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.