Proof of vaccination has long been part of the back-to-school checklist, but as the country emerges from the COVID-19 pandemic, Colorado’s childhood-immunization rates continue to drop. Pitkin County has seen a decline in vaccination rates at the preschool level over the past several years, while school-age rates have improved or held steady. 

The Colorado Department of Public Health and Environment recently released data on childhood immunization across the state that shows statewide drops in the percentage of students who have received vaccines. In some cases, experts say, this leaves communities vulnerable to outbreaks of preventable diseases such as measles. 

Some of the most pronounced declines in vaccine coverage were among students entering kindergarten in the 2022-23 school year. There are five vaccines required for kindergarten entrance; the percentage of Colorado students who are fully vaccinated for each of those reached its lowest level in at least six years. 

Colorado has set a goal of immunizing at least 95% of students against vaccine-preventable diseases. 

“No age, no vaccine is hitting this 95% from the past school year,” said Heather Roth, immunization branch chief at CDPHE. “Measles is what concerns me, because measles is so contagious. When you don’t have immunity upwards of [92% to 95%], it’s more likely that outbreaks are going to occur in communities.”

Only 86.8% of Colorado kindergartners had received the measles, mumps and rubella (MMR) vaccine in the 2022-23 school year. 

In Pitkin County, 96.7% of kindergartners had received the MMR vaccine. 

“Our K-12 rates are looking pretty darn good,” said Carly Senst, Pitkin County epidemiologist. 

Pitkin County’s immunization rates equal or exceed the state average for all vaccines in that age range for the 2022-23 school year. The state tracks vaccination for students in child care or preschools, for those entering kindergarten and for those entering grades K-12. 

Pediatric nurse Katy Stege injects a young patient’s leg with a vaccine at Aspen Valley Primary Care. Local preschools have seen a decrease in immunization rates, a trend health officials are working to reverse. Credit: Elizabeth Stewart-Severy/Aspen Journalism

Pitkin County aims to improve preschool vaccination rates after two-year decline

Although Pitkin County’s school-age rates are in good shape, preschool immunization rates are attracting public health officials’ attention; vaccination coverage has dropped 2.2% for MMR and 3.1% for DTAP ( which protects against diphtheria, tetanus and pertussis) over the past two years. 

“The immunization rates at the lower age group for our community in particular are a little bit more complex,” Senst said. 

Although average vaccination coverage remains relatively high, Senst said there are concerning areas. 

“When we look at individual school spaces, we can see certain pockets of vulnerability to vaccine-preventable diseases,” she said. 

Local school nurses collect immunization records and submit those to the state; they also follow up with parents who have not submitted records. The CDPHE also tracks compliance rates, which are a reflection of the percent of students who have submitted records showing either immunization or medical or nonmedical exemption. A very small number of students with severe allergies or other health issues receive medical exemptions to specific vaccines. Parents with religious or personal beliefs opposed to vaccination may take a short online course or speak with their pediatrician to obtain a nonmedical exemption to immunization. 

Some local child care centers have compliance rates at 90% or below. Senst pointed to a possible decrease in access to well-child visits during the COVID-19 pandemic and said the county is working to help students get vaccinated. 

“We’ve worked closely with those [child care centers] and set messaging out in order to try to increase immunization rates and to try to identify barriers for potentially why those schools aren’t reporting through this process,” Senst said.  

Pitkin County schools tend to have high rates of compliance. Aspen School District’s three public schools have compliance rates between 98.7% and 99.8%, compared with a statewide average of 91.9% of students in the K-12 age group. 

“Credit for that goes to school nurses, pediatricians and parents,” Senst said. “Our school nurses are really incredible.”

School nurses at the grade-school level and health consultants at the child care age work with families to collect immunization records or proof of exemptions. 

Maggie Gloor is the school nurse at Aspen Country Day School, which has a 100% compliance rate. She said she starts working with families to complete their vaccinations and records well before the school year starts. 

“Nobody really slips through the cracks,” Gloor said. “If somebody is behind [on the vaccination schedule], we find out why, and then work with them. There’s always the parent option, so we wouldn’t force somebody to get immunizations if they didn’t want them.”

Aspen Country Day School’s exemptions are higher than the state average, with 6% to 8% of the student population receiving nonmedical exemptions to vaccines. The state average is a 2.5% exemption rate. In Pitkin County, 4% to 5% of students in the K-12 grade range have received nonmedical exemptions to required vaccines. 

In 2019, the Colorado legislature passed a bill aimed at increasing vaccination and reducing the number of nonmedical exemptions. 

“We’ve firmed up the exemption process that’s allowable in the state of Colorado,” Roth said. “Prior to that bill being signed, a family could submit an exemption on a cocktail napkin to the school, and that would count.”

Now, there are standardized forms, and families requesting a nonmedical exemption either need to have a doctor or other qualified immunization provider sign off or need to complete an online course. 

Roth said it’s difficult to know if the program is working to reduce exemptions.

“We don’t have all the data,” she said. “We can’t really compare the data that we’re collecting now through the new exemption process with what existed before. It’s like apples to oranges.” 

Also, at the beginning of the pandemic, access to routine health care and well-child visits were restricted. 

“I think we’re still making our way back from that,” Roth said. 

Heather Prokaski, a child care health consultant with 12 local preschools and child care centers, collects, reviews and submits immunization records to the state. When students are missing immunizations, Prokaski notifies the child care center’s director, who follows up with families. 

“I saw an increase in children that were behind on their vaccinations,” Prokaski said of the years following the COVID emergency. When students are behind or missing vaccinations, parents have 14 days to develop a plan with their health care providers. 

 She said her job is not to encourage immunization but, rather, to document the parents’ decision, and it’s up to doctors to recommend vaccination. 

But when students don’t have regular access to a doctor, they may not be receiving that message. 

Aspen School District nursing staff — whose office is shown here — are responsible for keeping track of vaccination rates for local public school students. ASD immunization rates tend to be above the state average. Credit: Elizabeth Stewart-Severy/Aspen Journalism

State and county work to increase access to childhood shots

Health care access, which is a consistent challenge in many parts of the state, has been identified as one of Pitkin County’s top priorities for improvement. Roth said this is reflected in some of the state’s immunization data. 

“You’ll see some schools with really, really high noncompliance rates where kids just aren’t vaccinated. They don’t have any exemptions on file,” Roth said. “We have communities and students within schools that really have access barriers to finding vaccines that are convenient for them and their families.” 

The success of COVID-vaccination buses served as inspiration for a new state program aimed at increasing childhood immunization through mobile clinics. CDPHE rolled out a soft-launch this fall and has visited a few schools in the Denver metro area so far. 

“The schools that we’ve held clinics at had kids who were very far behind on vaccines and who didn’t necessarily have access to the traditional medical system,” Roth said. “Those have been metro-based, but I think that problem exists everywhere.”

The Colorado Department of Public Health and Environment’s Mobile Public Health Clinic aims to increase access to vaccination in low-income and underserved areas of the state. Pitkin County health officials are in talks with the state to bring mobile clinics to the Roaring Fork Valley. Credit: Courtesy photo

Senst said she is meeting with state representatives about potentially bringing childhood immunization clinics to the Roaring Fork Valley, as well as those for seasonal vaccinations.  

“We’re trying to do a little coordination with our county neighbors in order to utilize those clinics to best serve our uninsured and underinsured [populations] and increase access even for fully insured individuals,” Senst said. 

Immunization experts say it’s important to move quickly to address gaps in immunization coverage. Many of the childhood vaccines require multiple shots, and some are particularly beneficial to receive as a baby or toddler. 

“As we age, our immune systems change,” Senst said. “Our ability to react to certain immunizations does have a reduced benefit the older we get.”

For example, the polio vaccine isn’t typically given to adults because the immune response is not as strong and the vaccine doesn’t offer as much protection. 

“Catching these kids on time and making sure that they’re receiving these immunizations is important,” Senst said. “Trying to maximize that level of protection really has to do with receiving these immunizations on time.”

Aspen Journalism is supported by a grant from Pitkin County’s Healthy Community Fund. Aspen Journalism is solely responsible for its editorial content. 

Elizabeth Stewart-Severy is a freelance journalist based in Snowmass Village. She grew up in Aspen and has worked as an editor at Aspen Journalism, reporter at Aspen Public Radio and an English and journalism...