Childhood vaccine schedule has no link to diabetes, study confirms

A multi-institution epidemiological study found no evidence that the routine childhood immunization schedule is associated with the development of type 1 diabetes.

Researchers at eight integrated health care organizations in California, Colorado, Minnesota, Oregon, Washington and Wisconsin examined associations between three measures of the childhood immunization schedule and the incidence of type 1 diabetes in children aged 2 to 14 years.

Jason M. Glanz, PhD, a senior investigator at Kaiser Permanente’s Institute for Health Research and an associate clinical professor of epidemiology at the University of Colorado School of Public Health, said the study was a response to concerns some parents have about the vaccine schedule.

“One of the concerns that some parents have is the safety of the overall schedule, meaning there is some sort of risk to their child [getting] all of the vaccines as recommended, according to the schedule,” Glanz told Healio. “One of the specific concerns that parents might have is [a fear of] receiving too many vaccines at once might overwhelm their immune system.”

A previous report concluded that available data suggested the schedule was safe but that more research was needed, Glanz said.

“That was sort of the impetus behind this study, to look at the safety of the overall schedule, rather than individual vaccines,” Glanz said. “We chose diabetes because it's an autoimmune disease, and some parents have concerns about vaccines causing autoimmune diseases.”

Using a cohort of 584,171 children from the eight health systems, the researchers examined cumulative antigen exposure in the “first few years of life,” Glanz said, cumulative aluminum exposure through the first 14 months of life and whether either factor increased the risk for diabetes.

The study found that the average number of days unvaccinated and cumulative antigen exposure were not associated with type 1 diabetes. Cumulative vaccine aluminum exposure was associated with a reduced incidence of type 1 diabetes (adjusted HR = 0.89; 95% CI, 0.81-0.97).

“In this study, we didn't see any evidence that getting your vaccines on time increases the risk for an autoimmune disease like diabetes,” Glanz said. “That is something that pediatricians could theoretically use in conversation” with patients about the safety of vaccines.

Glanz said the researchers are interested in conducting similar studies with other autoimmune diseases, including allergies and asthma. He said some results pointed to aluminum actually reducing the risk for diabetes, a finding that “wasn’t expected,” and that more than an observational study would be required to confirm this.