Peer-reviewed article
Vaccine Coverage at 36 Months and 7 Years by Parental Birth Country, Washington State
Azadeh Tasslimi, Teal R. Bell, Tyler P. Moore, Charla A. DeBolt, Anisa Ibrahim et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study examined childhood vaccination coverage in Washington State among nearly 903,000 children born between 2006 and 2019, comparing those with at least one parent born outside the US to those with both US-born parents. Coverage for measles, mumps, rubella, pertussis, and polio vaccines at ages 36 months and 7 years varied substantially by parental birth country, ranging from 41% to 93%. Children with Filipino, Indian, or Mexican-born parents had higher vaccination coverage than those with US-born parents, while children with Moldovan, Russian, or Ukrainian-born parents had significantly lower coverage. The findings highlight important disparities in immunisation access across immigrant communities.
Key points
- 24% of children in the cohort had at least one non-US-born parent
- Vaccination coverage at 36 months ranged from 41.0% to 93.2% for MMR/polio and 32.6% to 86.4% for DTaP by parental birth country
- Children of Filipino-, Indian-, and Mexican-born parents were 3-16% more likely to be up-to-date on all three vaccines compared to children of US-born parents
- Children of Moldovan-, Russian-, and Ukrainian-born parents were 33-56% less likely to be up-to-date compared to children of US-born parents
- Similar patterns of disparity persisted at 7 years of age
Limitations
The study identifies disparities by parental birth country but does not explain the underlying reasons for these differences, such as access barriers, vaccine hesitancy, health beliefs, or socioeconomic factors. The cross-sectional design limits ability to understand causal mechanisms or changes over time within specific immigrant communities.
Abstract
BACKGROUND AND OBJECTIVES: Ensuring equitable vaccination access for immigrant communities is critical for guiding efforts to redress health disparities, but vaccine coverage data are limited. We evaluated childhood vaccination coverage by parental birth country (PBC) through the linkage of Washington State Immunization Information System data and birth records. METHODS: We conducted a retrospective cohort evaluation of children born in Washington from January 1, 2006 to November 12, 2019. We assessed up-to-date vaccination coverage status for measles, mumps, and rubella (MMR), diphtheria, tetanus, and pertussis (DTaP), and poliovirus vaccines at ages 36 months and 7 years. Children with ≥1 parent(s) born in selected non-US countries were compared with children with 2 US-born parents, using Poisson regression models to provide prevalence ratios. RESULTS: We identified 902 909 eligible children, of which 24% had ≥1 non-US-born parent(s). Vaccination coverage at 36 months by PBC ranged from 41.0% to 93.2% for ≥1 MMR doses and ≥3 poliovirus doses and 32.6% to 86.4% for ≥4 DTaP doses. Compared with children of US-born parents, the proportion of children up to date for all 3 vaccines was 3% to 16% higher among children of Filipino-, Indian-, and Mexican-born parents and 33% to 56% lower among children of Moldovan-, Russian-, and Ukrainian-born parents. Within-PBC coverage patterns were similar for all vaccines with some exceptions. Similar PBC-level differences were observed at 7 years of age. CONCLUSIONS: The linkage of public health data improved the characterization of community-level childhood immunization outcomes. The findings provide actionable information to understand community-level vaccination determinants and support interventions to enhance vaccine coverage.