More Missouri parents are opting their kindergarten-age children out of vaccinations for nonmedical reasons, according to state health department data.
Vaccination rates have been dropping statewide for several years. At the same time, religious exemptions – in which a parent or guardian declines to vaccinate their child with some or all required immunizations on the basis of sincerely held religious beliefs – are on the rise.
Doctors say the trend is putting Missouri's children at greater risk of outbreaks of measles and other infectious diseases.
"I definitely think it's an indication of mistrust. I think it's been increasing since COVID," said Dr. Kayce Morton, vice president of the Missouri chapter of the American Academy of Pediatrics. "The questioning and the mistrust in the medical and the health systems has increased the need for families to feel like they need to make these exemptions."
Missouri kindergarten students are required to show they're up to date on vaccines, including DTaP, polio, measles, mumps and rubella, chickenpox and hepatitis B. Like many states, Missouri allows some students to be exempt from those requirements for medical reasons or on the basis of religion.
In 2021, fewer than 3% of kindergarten students received nonmedical exemptions across all vaccine series, according to the Missouri Department of Health and Senior Services. In the 2025-26 school year, that rate more than doubled, to 5.7% statewide. At the same time, medical exemptions for students who are immunocompromised or otherwise unable to get vaccinated have remained relatively stable.
Different counties have vastly different exemption rates. In St. Louis and St. Louis County, the rate for religious exemptions for the measles vaccine is 2.3% and 3.4%, respectively. The rate is approximately 5.1% in St. Charles County.
In some counties, religious exemption rates are as high as 18%. Counties in the south and west part of the state as a whole have higher rates.
"It was very interesting to see the shift personally, [from] accepting parents to very questioning, concerned parents," said Morton, who works as a pediatric hospitalist near Springfield. "I just see lots and lots of kids coming in unvaccinated. Every week it's increased."
Morton said she's starting to see the effects. For example, Greene County has logged more cases of pertussis, sometimes called whooping cough, than in past years.
Religious exemptions
Those who wish to opt out on the basis of religion are required to fill out a DHSS-approved form and return it to their school administrator.
To get the form, families must click through a webpage advocating for the safety and effectiveness of the required vaccines.
"Actively choosing not to immunize a child by claiming a religious exemption is a parent's right; however, it carries significant responsibility," the page states. "To protect inadequately vaccinated individuals and the entire community, unimmunized children could be excluded from school during disease outbreaks."
Rising exemption rates can reflect how easy it is to receive a nonmedical reprieve, said Jennifer Layden, an infectious disease physician and epidemiologist at Washington University School of Medicine.
"I think people are looking for ways to potentially not be vaccinated, and if it's easy to get an exemption, then it creates a lower barrier for them to do so," she said.
However, Layden said making it more difficult to get exemptions will likely not solve the underlying issues of mistrust and confusion.
"It's [more about] having the conversation," she said. "Starting a conversation with, 'I understand you may have questions about vaccines. What can I answer for you?'"
Some religious groups and worldviews – including Christian Science and some naturopathic beliefs – consider vaccines to be unnecessary and harmful. Other people may object to ingredients, such as bovine serum, in certain immunizations.
"While there are examples of teachings that explicitly prohibit immunization, like those of faith healing denominations, most religious groups do not have straightforward teachings on the matter," wrote the Norwegian author of a 2023 study on the matter in the Academic Journal Vaccine: X.
Jesse Hackell, a retired pediatrician who has written many reports on vaccine policy for the American Academy of Pediatrics, takes the subject a step further:
"None of the mainstream religions – Christianity, Catholicism, Judaism, Islam, Buddhism – object to vaccination," he said. "In fact they consider it an obligation to safeguard yourself and those around you."
Hackell said parents should be allowed to opt their children out of vaccinations, though he wants every child who can to get the shots. But that means there may be consequences, such as not being able to attend schools or childcare facilities.
As fewer kids are vaccinated – for whatever reason – the risk of disease outbreaks increases. A base rate of vaccination is necessary to keep certain illnesses from spreading throughout a community. For measles, that rate is between 90% and 95%.
So far, there have been six recorded cases of measles in Missouri this year, according to federal data.
Earlier this week, state health officials warned of a potential measles exposure at a train station in Sedalia. The city is in Pettis County, with one of the highest nonmedical vaccination exemption rates – 15% – for the MMR vaccine.
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