The Last Mile Gap: Understanding Dropout Rates in the Measles Immunization Cascade in Rural Communities

Abstract

Background:
High initial vaccination uptake does not always translate to full immunization coverage due to dropouts before completion of the required doses. Understanding these gaps is critical for measles elimination goals.

Objective:
To identify the determinants of dropout between the first and second doses of measles-containing vaccine (MCV1 → MCV2) in rural primary health centers.

Methods:
A cross-sectional study was conducted in 48 rural health facilities in southern India between February and August 2023. Vaccination records of 4,326 eligible children aged 9–24 months were reviewed. Caregiver interviews captured sociodemographic and behavioral data. Logistic regression identified independent predictors of dropout.

Results:
The MCV1 coverage was 93.4%, while MCV2 coverage dropped to 78.9%, yielding a dropout rate of 15.5%. Major predictors included long travel distance to health facility (>5 km) (OR = 2.1, 95% CI: 1.6–2.8), caregiver’s lack of awareness about MCV2 (OR = 2.8, 95% CI: 2.1–3.7), and absence of reminder systems (OR = 3.4, 95% CI: 2.5–4.6). Mobile phone reminders reduced dropout odds by 42%.

Conclusion:
Strengthening reminder systems and improving caregiver awareness could substantially reduce measles immunization dropouts. Targeted interventions should focus on geographically remote households.