North Texas and Oklahoma have been experiencing the worst mumps outbreak in years.
More than 300 Oklahomans have been diagnosed, in Canadian, McClain, Osage, Tulsa, Woods, Kay, and Garfield counties, according to KWTV.
Texas, meanwhile, has seen the worst outbreak in a decade after steady declines, reports KCEN.
So, what’s going on? Dr. Buddy Creech directs a Texas vaccination research program. He says the problem is that more parents are choosing not to immunize their children.
The number of public school students opting out of immunizations is 19 times higher than it was 14 years ago. With fewer people getting vaccinations, the people who do get the vaccine fall under threat, too.
The MMR vaccine is 88 percent effective. But experts say the risk of the disease spreading falls drastically the more people are vaccinated.