Social Determinants of Childhood Vaccination Coverage in the United States: A Cross-Sectional Analysis of National Immunization Survey Data from 2010 to 2023 (Preprint)

BACKGROUND Vaccination in early childhood is essential to prevent serious infectious diseases and protect community health. In the United States (US), seven vaccines (DTaP, Polio, MMR, Hib, HepB, Varicella, PCV) are required for school entry, along with three others (HepA, Influenza, Rotavirus), which are recommended for full protection. Despite these guidelines, recent measles outbreaks in the US have drawn attention to persistent gaps in coverage. OBJECTIVE This cross-sectional study explores immunization patterns among children aged 19 to 35 months using provider-verified data from the National Immunization Survey-Child between 2010 and 2023. METHODS Survey-weighted logistic regression models were used to assess associations between vaccination status and social determinants of health, including child age group, maternal education, insurance status, birth order, and region. We considered the complex survey design to calculate vaccination coverage rates and their confidence intervals, accounting for clustering and stratification in the sampling methodology. A composite variable was created to measure full coverage of the seven recommended vaccines, and separate models were run for each vaccine to identify specific barriers to individual immunizations. RESULTS During the COVID-19 pandemic, we observed significantly less provider-verified data in general, creating challenges in trend analysis. The analysis revealed that older children, firstborns, and children of mothers with higher education levels had higher coverage rates, while Hispanic ethnicity and lack of insurance were consistently linked to lower uptake, especially for Hepatitis A, Influenza, and Rotavirus. Lower income-to-poverty ratios were also negatively associated with vaccination coverage across all vaccines studied. Regional and language-related disparities persisted throughout the years. CONCLUSIONS These findings underscore that current public health strategies have not fully addressed the deep-rooted social barriers to vaccination, pointing to the need for more focused, equity-driven interventions. Targeted outreach to vulnerable populations and policy changes addressing structural inequities are urgently needed to improve vaccination coverage. CLINICALTRIAL Not applicable (retrospective analysis of existing surveillance data)