The announcement coincides with a Lane County outbreak of whooping cough, or pertussis, which can be deadly, especially to infants

By Lynne Terry, Oregon Capital Chronicle

Oregon health authorities are worried about an infectious disease raging through schools, with almost one in 10 kindergarteners missing at least one required vaccination.

The Oregon Health Authority reported Thursday that nearly 9% of the state’s kindergartners had a nonmedical exemption this year, forgoing at least one of the required shots. That compares with about 8% in 2023 and almost 7% in 2022, marking the second consecutive yearly increase in the unvaccinated rate.

Last school year, Oregon had the second highest nonmedical exemption rate in the country after Idaho at 12%, according to the Centers for Disease Control and Prevention.

The trend worries Stacy de Assis Matthews, who oversees state immunization data.

“The concern is that a highly contagious disease, such as measles, will be introduced to a school that doesn’t have high immunization rates and that students will become sick,” Matthews said in a statement.

As of last week, there were more than 130 cases of measles in the U.S. in 2024, and about 80% of those patients were either not vaccinated against the infection or had no known vaccination status.

Measles, which has made a resurgence in recent years, is highly contagious and can be fatal. To prevent an outbreak, a high percentage of people need to have immunity against it, primarily through vaccination. The measles-mumps-rubella vaccine is highly effective against measles, provided enough people are vaccinated. Two doses are recommended, and it’s required for full-time college or university students.

Another worry: whooping cough or pertussis. Lane County just declared an outbreak in the community. Officials said the number of confirmed or suspected cases doubled within a week to about 40. They said some cases are linked, but others are scattered.

Health officials are concerned. 

“We are seeing a number of cases in very young children and at-risk populations,” Dr. Lisandra Guzman, Lane County’s deputy health officer, said in a statement. “Their health depends on our actions, so now is the time to do everything we can to protect them.”

Babies are especially vulnerable to a severe infection from pertussis: One in five treated in the hospital develops pneumonia and one out of 100 dies, according to the CDC. Infants can also develop violent, uncontrolled shaking and even encephalopathy, a brain disease.

Older children are also vulnerable, along with those who are pregnant and people with chronic medical conditions.

The best protection is immunization, health officials say. Whooping cough is among several diseases that are largely preventable by shots. Starting at two months, the state requires children to be vaccinated against several diseases, from polio, diphtheria, tetanus and pertussis to chickenpox and hepatitis A and B. Students have to submit their vaccination records to attend school, but the state allows nonmedical exemptions, provided parents watch an online educational presentation about the benefits of vaccination or obtain a certificate from a health care provider showing they’ve discussed vaccines.

Jonathan Modie, a health authority spokesman, said the state does not track the reasons for opting out.

“Some of these exemptions are likely due to parental beliefs, such as religious or personal beliefs, and some are likely due to challenges in families getting access to vaccination services,” Modie said in an email. “Some of these challenges could include cost barriers, problems being able to get a vaccine appointment at a local clinic.”

He said the health authority works with community organizations to try to increase vaccine access. There is also a free or low-cost state vaccination program for children without insurance, those on the Oregon Health Plan, the state’s version of Medicaid, and Indigenous residents.

Vaccination records are checked annually, and the state has an immunization system to remind families when their kids are past due for a shot. 

“School immunization laws help make sure kids can go to school in a safe and healthy environment free of vaccine-preventable diseases,” Matthews said. “These laws help support OHA’s goal of eliminating health disparities by 2030 by making sure each child’s immunization record is checked annually, and any child who is behind can be brought up to date on vaccines every year.”

State vaccine data through 2023 shows that vaccination rates against diphtheria, tetanus and pertussis, or DTaP, are the lowest. Modie suspects that’s because three shots are required for full immunization.

“If a child is missing even one dose of any of the vaccines in the series, then they won’t be counted as complete,” Modie said.

The next lowest, and for the same reason, Modie said, is immunization against pneumococcal disease, a bacterial infection that can cause mild to life-threatening symptoms. Four shots are required for full vaccination.

Most Oregon parents have their children immunized: 91.8% of students in kindergarten through 12th grade received all required vaccines in the 2022-23 academic year. 

Jackson County was at 87.7%, the fourth lowest rate of Oregon’s 36 counties, according to state data. The lowest rate was 85.1% in Grant County in Eastern Oregon, followed by the Southern Oregon counties of Curry (87.0%) and Josephine (85.2%).

Lynne Terry has more than 30 years of journalism experience, including a recent stint as editor of The Lund Report, a highly regarded health news site. She reported on health and food safety in her 18 years at The Oregonian, was a senior producer at Oregon Public Broadcasting and Paris correspondent for National Public Radio for nine years.