Routine vaccine uptake in school-aged autistic and non-autistic youth: A linked database study.

Objectives: This study was conducted to determine whether school-aged autistic youth received routine vaccines at a lower rate than their non-autistic peers.

Methods: In Nova Scotia (NS), Canada, vaccines routinely delivered in early adolescence are administered to Grade 7 students through a school-based Public Health vaccination program. NS youth eligible to receive Grade 7 vaccinations between 2011 and 2017 were included in this study. Autism spectrum disorder (ASD) diagnoses were determined from administrative health data. Rates of receipt of any Grade 7 vaccine and of individual vaccines were compared between autistic and non-autistic youth. Subgroup analyses included comparing Grade 7 vaccine receipt between autistic youth and their non-autistic siblings and early childhood vaccine receipt between autistic and non-autistic cohorts.

Results: The rates of receipt of any vaccine were 73% among 916 autistic youth and 82% among 49,599 non-autistic youth (adjusted relative risk = 0.91; 95% confidence interval = 0.87-0.95). Similar results were found for individual vaccines. Subgroup analyses revealed lower rates of Grade 7 vaccine receipt among autistic youth compared to among their non-autistic siblings. Rates of early childhood vaccine receipt did not differ between autistic and non-autistic cohorts.

Conclusion: Autistic youth were under-vaccinated compared to their non-autistic peers for Grade 7 vaccinations. Lower vaccination rates in autistic youth than in their non-autistic siblings suggest that setting-related factors may contribute more to the under-vaccination of autistic youth than parental vaccine hesitancy. Barriers to vaccine uptake for school-aged autistic youth, including those unique to school-based vaccination programs, must be explored and addressed.