The Centers for Disease Control and Prevention says more Oklahoma parents are seeking vaccination exemptions for their children.
The CDC's Kindergarten Survey found that Oklahoma's exemption rate increased by 0.3 percent between the 2016-17 and 2017-18 school years. The increase follows a national trend.
The Oklahoma Health Department says the state has three exemption categories: medical, religious or personal.
The CDC says 2.1 percent of Oklahoma public school students and 5.6 percent of private school students claimed at least one kind of exemption.
Researchers say parental vaccine hesitancy and the ease of obtaining an exemption may be factors contributing to the increase.
Lori Linstead is the director of Immunization Service for the state's Health Department. She says research shows that vaccines help protect people against certain preventable diseases.