Missouri parents are opting their kindergarten-age children out of required vaccinations at a rate that's climbed sharply in just a few years, with the statewide nonmedical exemption rate reaching 5.7% for the 2025-2026 school year, up from fewer than 3% in 2021. In some counties, religious exemption rates have soared as high as 18%, a shift playing out just as state health officials warn of active measles exposure risk along a central Missouri transit corridor.
The trend was detailed in reporting from St. Louis Public Radio, which found that southern and western Missouri counties tend to have the highest nonmedical exemption rates, while Pettis County recorded a 15% nonmedical exemption rate specifically for the MMR vaccine. Missouri law allows parents to decline required immunizations through medical or religious exemptions, and religious exemption applicants must fill out a Missouri Department of Health and Senior Services-approved form and return it to their school administrator. Under Missouri Revised Statutes Section 167.181 and state regulation 19 CSR 20-28.010, that means submitting Form Imm.P.11A signed by a parent or guardian, according to the Revised Statutes of Missouri.
Kindergarten students in the state must show they're up to date on DTaP, polio, measles, mumps, rubella, chickenpox and hepatitis B vaccines, per the station's report. Before receiving an exemption form, Missouri families must click through a webpage advocating the safety and effectiveness of required vaccines, the outlet noted. Medical exemptions, meanwhile, have remained relatively stable even as religious exemptions climb.
A Pediatrician on the Front Lines Near Springfield
Dr. Kayce Morton, a pediatric hospitalist near Springfield, told St. Louis Public Radio that increasing mistrust of medical and health systems has driven more families to seek vaccine exemptions. Morton reported seeing many unvaccinated children each week, according to the same account. The pattern lines up with regional data: the Springfield-Greene County Health Department recorded 21 pertussis cases in just the first 36 days of 2025, following 72 cases in 2024, both figures far exceeding the county's historic average of 13 cases per year, according to the Springfield-Greene County Health Department.
Whooping cough, as pertussis is commonly known, poses severe risks of pneumonia and life-threatening breathing pauses in infants. Greene County has logged more pertussis cases than in past years, per the station's reporting, part of a broader statewide slide in vaccination coverage that has stretched on for several years.
Exemption Rates Vary Widely Across the St. Louis Region
The gap between counties is stark even within the same metro area. St. Charles County had an approximately 5.1% religious exemption rate for the measles vaccine, while St. Louis County posted a 3.4% rate and the city of St. Louis came in at 2.3%, per St. Louis Public Radio's reporting. Yet a separate Missouri Department of Health and Senior Services fact sheet found St. Louis City's overall kindergarten MMR vaccination rate had fallen to just 75.4% in 2025 despite that low 2.2% religious exemption rate, according to the Missouri Department of Health and Senior Services, pointing to administrative noncompliance and incomplete record-keeping rather than deliberate opt-outs as the driver of the city's coverage gap.
Statewide, the department's data shows kindergarten MMR vaccination sitting at 89.5% in 2025, down from 94.6% in 2019 and below the 95% threshold generally needed for community herd immunity. Community measles vaccination coverage needs to be between 90% and 95% to limit disease spread, per the station's reporting. Jennifer Layden said easy access to exemptions creates a lower barrier to avoiding vaccination, and warned that Missouri children face greater risk of measles and other infectious-disease outbreaks as a result.
Religious Objections and What Faith Traditions Actually Teach
Some families cite objections to ingredients such as bovine serum in certain immunizations, while others draw on naturopathic beliefs that consider vaccines unnecessary and harmful, or on Christian Science teachings that consider vaccines unnecessary and harmful. But Jesse Hackell, who supports allowing parents to opt their children out of vaccinations, said mainstream religions generally consider vaccination an obligation to safeguard oneself and others rather than something to avoid. A 2023 study reported that most religious groups do not have straightforward teachings on immunization one way or the other, according to the study's author as cited by the station.
Layden recommended conversations that address parents' vaccine questions directly, but cautioned that making exemptions more difficult will likely not solve the underlying mistrust and confusion driving the trend. Children who opt out of vaccinations may be unable to attend schools or childcare facilities during declared outbreaks — Missouri regulation 19 CSR 20-28.010 authorizes local health authorities and school administrators to immediately exclude unimmunized students from school or day care during a vaccine-preventable disease outbreak until the emergency is declared over, per the regulation's text. Those exclusion rules apply regardless of whether an exemption form is on file.
Measles Exposure Warning Follows Amtrak Trip Through Sedalia
The stakes of that immunity gap came into sharp focus this month. On September 9, the Missouri Department of Health and Senior Services issued a public alert warning of potential measles exposure after a confirmed measles patient boarded an Amtrak train in Sedalia traveling toward Chicago on August 27, according to a bulletin from the department. Measles is an airborne virus that can remain infectious in the air for up to two hours after an infected person has left an area. State health officials warned of the potential exposure at the train station in Sedalia, and federal data shows Missouri had recorded six measles cases in 2026.
That local incident sits inside a much larger national surge. The Centers for Disease Control and Prevention reported 2,144 confirmed measles cases across the United States in 2025, with 93% occurring in unvaccinated individuals — the highest annual case count since measles was declared eliminated in the U.S. in 2000, according to the CDC. National kindergarten vaccine exemption rates reached an all-time high of 4.2% in the 2025-2026 school year, up from 3.6% the year before and 3.3% the year before that, per the CDC's SchoolVaxView data.
Missouri has faced this kind of localized disruption before. In March, Principia School temporarily barred students without proof of immunity from its St. Louis County campus for 21 days following a confirmed chickenpox outbreak. Hoodline also previously reported that Missouri's kindergarten religious exemption rate had climbed to 6% in the 2025-2026 school year, tied to the state's statutory exemption process, and that Missouri was swept up in a broader multistate measles surge during 2025.
