Evaluation of vaccination coverage and dropout rates among children aged 12–23 months in the slums of Mumbai, India: Preliminary analysis of a cross sectional study

Adequate vaccination coverage under any national immunization programs against six vaccine preventable diseases is crucial to reducing infant mortality. India has one of the lowest vaccination coverage rates in the world. Where immunization coverage is low, vaccine preventable diseases contribute to worse health outcomes, particularly in slums where 33% of the Indian urban population live.

To explore the vaccination coverage and the dropout rates of primary vaccination among children aged 12–23 months under the national immunization program in the slums of Mumbai, Maharashtra, India.

A community based cross-sectional cluster survey was conducted in slum households of Mumbai. Parents or caretakers of 550 eligible children aged 12–23 months were interviewed using a structured interview schedule. Sample size was calculated using the WHO vaccination coverage cluster survey methodology.

Out of a total of 550 children, 73.1% were fully vaccinated, 23.8% were partially vaccinated, and 3.1% were reported unvaccinated. This study revealed higher dropout rate for BCG-DPT3 (18.3%) and DPT1-DPT3 (12.8%) vaccines than the target cutoff of 10%. We observed a gender differences in vaccination coverage as dropout rates for all vaccines was found to be higher in female children.

In this study, full vaccination coverage is below the expected level of >80.0%. The importance of full vaccination is still not felt in the slum populations. Strategies should be focused on reducing the dropout rates by tracking eligible children and raising awareness about the importance of full vaccination.