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KBIA’s Health & Wealth Desk covers the economy and health of rural and underserved communities in Missouri and beyond. The team produces a weekly radio segment, as well as in-depth features and regular blog posts. The reporting desk is funded by a grant from the University of Missouri, and the Missouri Foundation for Health.Contact the Health & Wealth desk.

Fewer children in Missouri are getting vaccinated - and experts are concerned

Centers for Disease Control and Prevention
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Unsplash

In Missouri, all children enrolled in and attending school - public or private - are required to receive certain immunizations unless they have an exemption. But recent data from the Missouri Department of Health and Senior Services shows that vaccination rates are dropping and religious exemptions are rising among the state’s children.

This is a graphic with 5 bar charts showing rates for 5 required vaccinations among kindergarteners in Missouri from 2016-2024 academic years. The 5 required vaccines are DTaP, IPV/Polio, MMR, Hep B and Varicella.
Bureau of Immunizations
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Missouri Department of Health and Senior Services
Rates for 5 required vaccinations among kindergarteners in Missouri from 2016-2024 academic years.

Five vaccines are required for all school-age children: Polio, MMR (measles, mumps and rubella), Hepatitis B, Varicella (chicken pox) and DTap (tetanus, diphtheria and pertussis). In addition, 8th graders are required to receive the meningococcal vaccine and a Tdap booster.

The Missouri Department of Health and Senior Services’ (DHSS) Bureau of Immunizations releases annual reports that track immunization rates for kindergartners and 8th graders. Vaccination rates among kindergartners have been declining since 2018 for all five required vaccines. Around 2020, vaccination rates began to drop more sharply - and rates among 8th graders began dropping as well. 

Lynelle Paro, bureau chief of the Bureau of Immunizations, said that for the 2023-2024 school year, rates were lower for both age groups that are tracked.

“We are trending in not as many fully immunized children across the board,” Paro said. “Probably more significant in the kindergarten data, simply because that's when a child goes into school with all new requirements, whereas with eighth grade, it's only that Tdap and the meningococcal that are new requirements that they would not have already had as a kindergartner through seventh grader.”

This is a graphic with 2 line graphs showing rates of Missouri kindergarteners with religious or medical exemptions from required vaccinations on file for academic years 2016-2024
Bureau of Immunizations
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Missouri Department of Health and Senior Services
Rates of Missouri kindergarteners with religious or medical exemptions from required vaccinations on file for academic years 2016-2024

Religious exemptions on the rise

All Missouri students are required to get immunizations unless their guardians have filed an exemption. There are two types of exemptions - medical and religious. Medical exemptions must be signed by a medical professional, while religious exemptions are signed by a parent or guardian.

In the 2023-2024 school year, 4.3% of Missouri kindergartners had a religious exemption on file. Paro said that’s a significant increase from the previous school year, when only 3.5% of kindergartners had one on file. That represents an increase of about 500 more students with religious exemptions, year-over-year.

“It really has been happening over a long period of time. I mean, we've seen, each year, a slight increase in the exemption rates - the religious exemption rates - but from [the] 2020-2021 school year until now, we've seen a very steep increase,” Paro said.

This is a graphic with 2 line graphs showing rates of Missouri eighth graders with a religious or medical exemption from a vaccine on file for academic years 2016-2024.
Bureau of Immunizations
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Missouri Department of Health and Senior Services
Rates of Missouri eighth graders with a religious or medical exemption from a vaccine on file for academic years 2016-2024

In the 2018-2019 school year, before the impact of COVID-19, Missouri’s religious exemption rate among kindergartners was 2.4% - a little more than half of what it is now.

Among the 8th grade population, the religious exemption rate has remained more stable - but has still increased each year since the 2020-2021 school year. Paro said that the state knows how many exemptions are filed, but the reasons for the exemptions are not reported to them - meaning the state has no real way of knowing why the exemption rate has continued to rise.

“We can speculate that it's because parents don't want their child to have to be vaccinated for COVID, so they place an exemption on file. Some of it is just parents have, through the years, become a little more vaccine hesitant, or placing exemptions on file so a school may not know their exemption or their vaccination history,” Paro said. “But we don't know an exact reason.”

Part of a national trend

This is a graphic with several bar charts showing vaccination rates for 6 required vaccines among eighth graders in Missouri for academic years 2016-2024. The 6 vaccines tracked are Tdap, MCV, IPV/Polio, MMR, Hep B and Varicella.
Bureau of Immunizations
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Missouri Department of Health and Senior Services
Vaccination rates for 6 required vaccines among eighth graders in Missouri for academic years 2016-2024

According to the Centers for Disease Control and Prevention, vaccination trends like these aren’t unique to Missouri. Religious exemption rates for vaccines among children began rising nationally after the COVID-19 pandemic and reached 3% in the 2022-2023 school year - a rate the CDC says is the highest ever reported in U.S. history.

A 2023 report from the CDC said that states must keep their overall exemption rates for childhood vaccinations under 5% to make sure there’s enough vaccination coverage to prevent outbreaks. As of 2023, 10 states already exceed that threshold for kindergartners.

Childhood vaccination rates have also been falling nationwide - a change the CDC says can also be attributed to COVID. However, rates aren’t returning to pre-pandemic levels, and CDC researchers have said that could be harmful to herd immunity at the state and national level.

Falling rates could impact herd immunity

Dr. Alexandra James, a pediatrician with MU Health Care in Columbia, said she thinks of herd immunity like an armor.

“As a general population, when we all participate and get vaccinated, we have a collective armor that doesn't even allow many and most of these conditions to penetrate,” James said. “The more chinks we have in that armor, aka, the more people who are unvaccinated, then the more likely that those viruses and bacteria, those conditions, as illnesses can come in and affect everyone.”

This is a bar chart depicting change in percentage of kindergartners exempt from one or more vaccinations, by jurisdiction — United States, 2021–22 and 2022–23 school years. Connecticut, Maine, Georgia, North Dakota and California saw drops in their exemptions rates, while Hawaii, Oklahoma, Louisiana, Idaho and Oregon has the largest increases in their exemption rates. Missouri had around a 1% increase.
Centers for Disease Control and Prevention
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National Institutes of Health
Change in percentage of kindergartners exempt from one or more vaccinations, by jurisdiction — United States, 2021–22 and 2022–23 school years * Montana did not report kindergarten vaccination coverage for the 2021–22 and 2022–23 school years and is excluded from this analysis. Utah changed the way data were reported between the 2021–22 and 2022–23 school years and is excluded from this analysis.

According to the U.S. Department of Health and Human Services, herd immunity occurs when enough people are vaccinated against a virus that an entire community is protected. Dr. James said that each vaccine is different when it comes to how many people need to receive it to achieve herd immunity - but in general, falling immunization rates and rising exemption rates can be a bad sign.

At the Bureau of Immunizations, Paro said that falling immunization rates have already caused herd immunity to drop off in some parts of the state for measles, which can be prevented through the MMR vaccine. 

“We have pockets of the state that are below that herd immunity level because of the exemptions and and the lack of fully immunized children in that area. So that becomes a great concern when you're looking at the potential to have a vaccine preventable outbreak in that area because of the low vaccination coverage rates,” Paro said.

When herd immunity declines, the risk of measles outbreaks increases. According to the CDC, the COVID-19 pandemic created a major setback for measles vaccination in the U.S., and measles outbreaks have become more common.

Dr. James said that declining herd immunity can be dangerous for everyone - especially children who are immunocompromised from conditions such as cancer and can’t receive vaccines.

“The less people that make that collective decision, the more susceptible we are as an entire population to see these diseases re emerge, and to see the complications from those diseases, such as hearing loss. So kids had the possibility for deafness from measles,” James said.

An effort to raise rates in Missouri

Dr. Jane McElroy is a professor of Family and Community Medicine at the University of Missouri School of Medicine and a principal investigator of a collaborative pilot project between MU School of Medicine, DHSS, Washington University and the Missouri Immunization Coalition.

“The focus of the project is to work directly with clinicians to have them improve their immunization rates for children and adolescents,” McElroy said.

The project came about at a Rural Health Research summit, where McElroy said clinical leaders from the Missouri Primary Care Innovation Network began talking about their declining childhood vaccination rates and how to increase them.

Lynelle Phillips, board president and acting co Interim Executive Director for the Missouri Immunization Coalition, said the project works by enrolling clinicians that are given evidence-based resources and interventions to increase immunization rates among the children they treat.

“One of the strategies here is to assure that the clinicians are most up to date on all of the particulars with childhood immunizations and also communication strategies for vaccine hesitant parents,” Phillips said.

Moving forward, Phillips said the team is talking with 28 clinicians representing 18 clinics throughout Missouri about the challenges they face and what might need to change to make the project a success.

“We may need to look into more innovative strategies that are specific to Missouri, to our social context, to help them improve immunization rates,” Phillips said.

Anna Spidel is a health reporter for the KBIA Health & Wealth desk. A proud Michigander, Anna hails from Dexter, Michigan and received her Bachelor of Arts in Journalism from Michigan State University in 2022. Previously, she worked with member station Michigan Radio as an assistant producer on Stateside.
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