Oregon child vaccination rates plummet to record low as opt-outs surge

Oregon's kindergarten vaccination rates have fallen to their lowest point in modern record-keeping, with nonmedical exemptions claiming a record 11% of students and fewer than 86% of kindergarteners fully vaccinated against preventable diseases. The new data from the Oregon Health Authority, released Thursday, confirms what public health officials have feared: a decade-long decline that has steepened dramatically since 2022 is now pushing communities dangerously close to the threshold where outbreaks become not just possible, but inevitable.

The numbers tell a clear and worrying story. In the 2021-22 school year, 88.4% of Oregon kindergarteners were fully vaccinated. Four years later, that figure has dropped by roughly 3 percentage points, while nonmedical exemptions — claimed by parents for personal or religious reasons, not medical necessity — have climbed from roughly 7% to 11%. For the measles, mumps, and rubella vaccine specifically, nearly 1 in 10 kindergarteners now have a nonmedical exemption, nearly double the rate from a decade ago.

The consequence is already visible. More than one-third of Oregon schools have measles vaccination rates below 93%, the coverage level that epidemiologists consider the minimum threshold for community protection against measles — one of the most contagious viruses known to medicine. A single infected person in a room with unvaccinated individuals can transmit measles to 90% of those susceptible. These under-vaccinated schools are spread across all 36 Oregon counties, meaning the risk is not concentrated in a few pockets but distributed statewide.

Oregon is simultaneously grappling with its worst whooping cough outbreak in 75 years. The state reported 1,475 pertussis cases in 2025, driven in part by declining DTaP vaccination rates. Pertussis is particularly dangerous for infants who are too young to be fully vaccinated; they depend on the herd immunity of the community around them. That herd immunity is eroding.

Dr. Howard Chiou, medical director for communicable diseases and immunizations at OHA's Public Health Division, put it plainly: although the vast majority of families in Oregon are still choosing to protect their children through vaccination, the downward trends are deeply concerning. We risk seeing the return of diseases such as measles and polio — diseases that are entirely preventable with vaccines. The framing is deliberate. These are not hypothetical threats. Measles was declared eliminated in the United States in 2000. It is now back, with outbreaks reported in multiple states in 2025. Polio, while not circulating in the U.S., remains endemic in parts of the world and requires sustained vaccination to prevent reintroduction.

The statewide average of 90.2% vaccination for K-12 students masks the severity of the local problem. A school with 95% coverage and a school with 75% coverage can average out to a reassuring number while one community sits on the edge of an outbreak. As Chiou noted, parents should not assume their local schools will also be well protected.

Oregon is not alone in this trend, but it is among the most affected. The state's relatively permissive exemption laws make it easier for parents to opt out of required vaccinations without providing a medical reason. States that have tightened exemption requirements — California, Maine, and New York among them — have maintained higher vaccination rates. The policy lesson is straightforward: when you make it harder to skip vaccines, fewer people skip vaccines. Whether Oregon's legislature acts on that lesson is a political question with medical consequences.

What This Means For You: If you have children in school — in Oregon or anywhere in the United States — the vaccination rate at your specific school matters more than the statewide average. Ask your school for its current immunization rate. If it's below 95% for MMR, your child is at increased risk even if they are fully vaccinated, because no vaccine is 100% effective and herd immunity is what protects everyone. If you live in a state with easy nonmedical exemptions, your legislature has made a policy choice that makes outbreaks more likely. This is not a theoretical concern — Oregon is already dealing with a whooping cough outbreak at levels not seen in 75 years, and measles is circulating in multiple states. The vaccines work. The question is whether enough people around you have chosen to get them.