Missouri students are heading back to school, but immunization rates continue to lag
By: Gabrielle Teiner
COLUMBIA, Mo. (KMIZ)
In less than a month, students across Missouri will be preparing to head back to the classroom for the 2025-2026 school year.
As the new school year approaches in Missouri, state health officials are urging parents and guardians to check their child's vaccination status, warning that falling immunization rates could lead to outbreaks of preventable diseases.
Immunization rates in both private and public schools continue to fall across Missouri, following a national trend. Data from Johns Hopkins University in June shows that in 78% of counties across the country, vaccination rates for the MMR vaccine, which protects against measles, mumps and rubella, have fallen more than 2% since before the pandemic.
Health officials say that drop, combined with a rise in exemption requests, has weakened herd immunity protection from vaccine-preventable illnesses, a concern highlighted by a recent measles outbreak in Cedar County and Taney County in Southwest Missouri.
"We've seen a lot of infectious diseases that previously have been prevented and even thought to be eliminated have started to come back," said Dr. Laura Morris, who is a chief medical officer for ambulatory care at MU Health Care and serves as an American Academy of Family Physicians liaison to the Advisory Committee on Immunization Practices. "It's really important to keep students up to date because that's really what helps to protect our schools and to keep kids safe and healthy."
A total of seven cases of measles have been confirmed in Missouri in 2025, though measles was declared eliminated in the United States in 2000, which was achieved through high vaccination rates. As of July 22, the Centers for Disease Control and Prevention reports a total of 1,319 confirmed measles cases across the country, with 29 outbreaks reported, making it the worst measles outbreak in more than 30 years. Those outbreaks resulted in 87% of cases reported.
"We have seen cases of measles pop up in Missouri, and in surrounding states," Morris said. "In fact, the United States has already had more measles cases this year in only half of the year than in decades."
Measles is a highly contagious, airborne disease that can spread through coughing, talking, sneezing or touching contaminated surfaces, where it can live for up to two hours. Measles can be very dangerous to babies and immunocompromised people, with one in five people developing pneumonia. In some cases, brain infection, brain swelling or death can occur.
"Measles can make your immune system forget the protection that you have against other infections, so it causes immune system amnesia, is what we'll call it," Morris said. And that's really important because now you're at a higher risk after recovering from measles for other infections. Measles can have long-term complications for decades after that."
"When vaccination rates drop, measles is the first one that pops up and pertussis is also on the rise for the same reason; it is the next-most infectious disease, among vaccine-preventable infections," said Dr. George Turabelidze, who is a pediatrician and state epidemiologist. "If we continue that decline, we will start seeing mumps, we will see chicken pox and all those things."
According to data from the Department of Health and Senior Services, there is no specific school-required vaccination rate falling. It's all of them.
"It's a trend nationwide, so not here alone in Missouri, but there is definitely a trend for families to want to opt out or to exempt their students from the vaccine requirements," Morris said.
Kindergarten public school vaccination rates for required immunizations:
| School Year | DTaP | Hep B | IPV/Polio | MMR | Var |
| 19-20 | 94.7% | 96.1% | 95% | 94.9% | 94.4% |
| 20-21 | 92.5% | 95.5% | 93% | 92.7% | 92.4% |
| 21-22 | 91.5% | 94.2% | 92% | 91.9% | 91.3% |
| 22-23 | 91.2% | 93.9% | 91.6% | 91.7% | 91.1% |
| 23-24 | 90.7% | 93.6% | 91.2% | 90.9% | 90.4% |
Data obtained from the Missouri Department of Health and Senior Services.
Kindergarten private school vaccination rates for required immunizations:
| School Year | DTaP | Hep B | IPV/Polio | MMR | Var |
| 19-20 | 93.4% | 94.4% | 93.9% | 91.5% | 91.1% |
| 20-21 | 92.9% | 93.5% | 92.6% | 90.8% | 88.9% |
| 21-22 | 90.6% | 92.1% | 90.9% | 88.9% | 88.4% |
| 22-23 | 89.9% | 91.4% | 90.2% | 87% | 86.7% |
| 23-24 | 88.9% | 90.7% | 89.1% | 85.4% | 85.1% |
Data obtained from the Missouri Department of Health and Senior Services.
A key percentage to note is the falling MMR vaccination rates. Turabelidze said while Missouri's overall protection rate is tolerable for measles, it's barely above the threshold for herd immunity in most counties. That can be achieved when 95% of a community is fully vaccinated by two doses of the MMR vaccine, according to DHSS. Two doses of MMR provide 97% lifetime protection against measles.
Morris said cases of pertussis -- a vaccine-preventable disease also known as whooping cough -- are also on the rise. In 2024, there were six times as many cases reported compared to 2023, according to the CDC. In 2025, the number of cases is trending downward, but remains high.
"The 90% range, that's not enough to provide herd immunity and unfortunately, I think because of that, we will likely see outbreaks in Missouri and potentially, schools are going to be one of those sources," Morris said.
Health officials say multiple factors are contributing to the decline, which Morris said has been going on since the mid-2010s. Those include more families choosing to exempt their child from immunizations, vaccine hesitancy and the spread of vaccine misinformation.
By law in Missouri, any child attending school, either private or public, must have their vaccinations to attend school; however, the state does allow medical and religious exemptions.
A medical exemption is granted when a child's physician determines the child is allergic to a component of the immunization, has an immune deficiency or has an illness (such as cancer). A student would need a signed certification from a licensed medical doctor indicating the immunization would seriously endanger the student's health or life, or the student has documentation of previously having the disease and there is laboratory evidence of immunity.
"In the state of Missouri, we have about a 0.2% rate across kindergarten specifically, of medical exemptions," said Lynelle Paro, who is the chief of the Missouri Bureau of Immunizations. "Vaccine exemptions in Missouri are calculated by antigen or vaccine, rather than by children."
Paro said medical exemptions are not as common, and Turabelidze agreed, saying the exemption typically only is for one vaccination, not the whole lot.
