Failure to Complete Multidose Vaccine Series in Early Childhood

Area of Science:

• Pediatric Health
• Public Health
• Vaccinology

Background:

• Optimal protection from early childhood immunizations typically requires a series of 3 to 4 doses.
• Understanding factors contributing to incomplete vaccination series is crucial for public health.

Purpose of the Study:

• To identify sociodemographic factors associated with initiating but not completing multidose vaccine series in US children.
• To inform strategies for improving childhood vaccination coverage.

Main Methods:

• Analysis of 2019 National Immunization Survey-Child data for US children aged 19-35 months.
• Classification of vaccination patterns: series completion, series initiation failure, or multidose series incompletion.
• Multivariable log-linked binomial regression to assess associations between sociodemographic factors and vaccination patterns, accounting for survey design and weighting.

Main Results:

• 17.2% of children initiated but did not complete at least one multidose vaccine series.
• Key factors associated with incomplete series included moving across state lines (aPR=1.45), household size (aPR=1.29-1.68), and lack of insurance (aPR=2.03).
• Approximately 8.4% of children were only one dose away from completing the 7-vaccine series.

Conclusions:

• Over 1 in 6 US children face barriers to completing multidose vaccine series, highlighting systemic issues.
• Enhanced strategies are necessary to improve multidose vaccine completion rates.
• Achieving vaccination coverage goals requires addressing these identified structural barriers to ensure optimal protection against preventable diseases.