Key Takeaways
Extended Takeaways
- The comparison group in this study was within-family: typically developing elder siblings had higher complete vaccination (85%) and MMR uptake (86%) than both probands and younger siblings, which points to a change in family vaccination behavior rather than a background community rate.
- Vaccination gaps were not limited to autism spectrum disorder; the sample was dominated by global developmental delay/intellectual development disorder (43.4%), with ASD accounting for 15.9%, suggesting hesitancy may extend across developmental disabilities seen in child development centers.
- There was no significant difference in either overall vaccination status or MMR vaccination status between children with developmental disabilities and their younger siblings, so clinicians should assess vaccine completion across all children in the household rather than focusing only on later-born siblings.
- No association was found between vaccination status and parental education, paternal occupation, or religious beliefs in this sample, indicating that counseling should not rely on sociodemographic assumptions when addressing vaccine hesitancy in families of children with developmental delay.
- The study identified a particularly large MMR gap at age 18 months, with uptake at 60% in children with developmental disabilities and 59% in younger siblings versus 86% in older siblings; this makes the MMR visit a practical point for anticipatory counseling and correction of autism-related vaccine fears.
