SALEM, Ore. (KATU) — Oregon’s childhood vaccination rates have fallen to their lowest levels on record, while the number of parents claiming nonmedical vaccine exemptions continues to climb, according to newly released data from the Oregon Health Authority.

The agency reported on Thursday that 85.6% of Oregon kindergarteners were up to date on required vaccines during the 2025-26 school year.

At the same time, the nonmedical exemption rate reached a record high of 10.9%.

State health officials say the trend is raising concerns about the potential for outbreaks of highly contagious diseases, including measles and whooping cough.

“Although the vast majority of families in Oregon are still choosing to protect families through vaccination, the downward trends are deeply concerning,” said Dr. Howard Chiou, medical director for communicable diseases and immunizations at OHA. “We risk seeing the return of diseases such as measles and polio—diseases of the past that once caused widespread harm but are entirely preventable with vaccines.”

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The statewide numbers tell only part of the story.

According to OHA, more than one in three Oregon schools with at least 10 students have measles vaccination rates below 95%, the threshold public health officials say is needed to help prevent outbreaks through community immunity.

Chiou said those exemption rates, combined with lower vaccination coverage at some schools, are increasing the risk of disease outbreaks.

The concerns come as Oregon and the nation are seeing increases in vaccine-preventable diseases.

OHA says the nonmedical exemption rate for the second dose of the measles vaccine has nearly doubled over the past decade, rising from 4.9% to 9.4%.

The state also recorded 1,475 cases of pertussis, or whooping cough, in 2025, the highest total in 75 years.

What could happen if the trend continues?

Dr. Alanna Braun, a pediatrician at OHSU, said declining vaccination rates increase the likelihood of disease outbreaks.

“The thing that really stands out to me the most is just sort of the trend of just ongoing decreased immunization rates across our state and seeing how many schools here in Oregon are now at risk for major outbreaks of some really serious illnesses,” said Braun.

Braun said communities become more vulnerable when vaccination rates fall below the level needed to prevent the spread of disease.

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She noted that outbreaks can affect more than just unvaccinated students.

“A lot of kids have infant siblings at home who are not able to be vaccinated,” Braun said. “Certainly, there are kids in all of these schools who are unable to be vaccinated, kids who are undergoing chemotherapy for cancer. There are teachers who are immunocompromised for various reasons.”

Braun said the long-term outlook is concerning if vaccination rates continue to fall.

“As we’re seeing reduced rates of immunizations, I think it’s more and more likely that we are gonna see some of these preventable illnesses with more frequency,” she said.

What parents can do

OHA is encouraging parents to check vaccination rates at their child’s school and talk with their healthcare provider if they have questions about vaccines.

“We want to empower families to make informed decisions,” said Chiou. “We want parents to revisit and reconsider their decisions because the situation in Oregon has changed.”

Parents can view vaccination and exemption rates for individual schools using OHA’s School Immunization Data Dashboard.