Year of Award
2025
Document Type
Dissertation
Degree Type
Doctor of Philosophy (PhD)
Degree Name
Public Health
Department or School/College
School of Public and Community Health Sciences
Committee Chair
Sophia R Newcomer
Commitee Members
Ethan Walker, Jon Graham, Claire Adam, Rachel Peterson
Keywords
vaccine epidemiology, health services, childhood vaccinations, public health
Abstract
Background: From 2011-2021, the U.S. Advisory Committee on Immunization Practices (ACIP) recommended 10 vaccine series by age 24 months, with guidelines for minimum vaccination age, maximum age for rotavirus vaccination, minimum dose intervals, and a catch-up schedule for delayed series initiation. National vaccination surveillance evaluates series completion based on whether children received the recommended number of doses, including a combined 7-vaccine metric (completed seven series collectively). However, this approach overlooks: 1) vaccinations given too early, too late, or too close together, 2) catch-up schedule vaccinations, and 3) completion of all 10 recommended vaccines.
Purpose: To refine national childhood vaccination coverage measures to better reflect ACIP recommendations and identify factors associated with schedule use and adherence.
Methods: I analyzed 2011-2021 publicly available National Immunization Survey-Child (NIS-Child) data for children aged 19-35 months with provider-verified vaccine records. I quantified vaccinations administered outside of ACIP’s age guidelines (Aim 1) and pneumococcal (PCV) and Haemophilus influenzae type b (Hib) doses given late enough to trigger the ACIP catch-up schedule (Aim 2). Using logistic regression, I determined sociodemographic and provider factors influencing ACIP adherence. I calculated a combined 10-vaccine series measure encompassing all recommended vaccines and used a Cox proportional hazards model to identify factors associated with combined series completion (Aim 3).
Results: Between 2011 and 2020, 15.4% (95% CI:15.0-15.8%) of U.S. children received at least one dose too early, too late, or too soon after a prior dose. From 2016 to 2021, 2.5% (95% CI: 2.2–2.7%) and 2.3% (95% CI: 2.1–2.5%) of children initiated PCV or Hib series late enough to trigger the ACIP catch-up schedule, respectively. Only 40.2% (95% CI: 39.2–41.1%) of U.S. children completed the combined 10-vaccine series—27 percentage points below the nationally reported combined 7-vaccine series metric, with influenza being the primary contributor to reduced coverage.
Conclusion: This study highlights the impact of nuanced vaccination measures on national schedule adherence estimates and suggests refinements to measurement methods that can better identify specific areas for improvement in immunization service delivery.
Recommended Citation
Albers, Alexandria Nicole, "REFINING POPULATION-LEVEL MEASURES OF EARLY CHILDHOOD VACCINATION COVERAGE USING NATIONAL IMMUNIZATION SURVEY-CHILD DATA" (2025). Graduate Student Theses, Dissertations, & Professional Papers. 12432.
https://scholarworks.umt.edu/etd/12432
© Copyright 2025 Alexandria Nicole Albers
