Idaho Department of Health and Welfare officials say more parents are refusing to immunize their children.
It's the fifth year in a row that the number of people claiming vaccination exemptions has increased.
The Times-News reports that for the current school year, close to 370 children in south-central Idaho were exempted from vaccinations. That's about 4 percent of the kids enrolled in school in the region.
Idaho requires students in kindergarten through seventh grade to receive several immunizations before attending school, including vaccines for tetanus, pertussis and polio. But the state allows parents to exempt their kids for medical, religious and philosophical reasons.
South Central Public Health District Nurse Lisa Klamm says as more children stop getting the shots, the chances of catching potentially fatal diseases like polio increase.