INTRODUCTION:
Urban poor and migrant populations remain disproportionately represented among zero dose and dropout children, despite national and subnational progress in routine immunization. Barriers such as high mobility, informal housing, fragmented service access, and vaccine hesitancy contribute to persistent coverage gaps that undermine equity goals. This study evaluates a community-led model implemented across six urban primary health centres (UPHCs) between October 2024 and October 2025 to identify missed children and improve zero dose conversion in high-risk settlements.

METHODS:
A mixed-methods approach included house-to-house surveys, participatory rapid assessments, social mapping, community meetings, and coordination with frontline health workers. Quantitative indicators included the number of zero dose children identified, linked, and vaccinated. Qualitative insights were obtained from counselling interactions and community discussions. A total of 2256 households across high-risk migrant settlements were visited. Data were compiled from routine program documentation.

RESULTS:
Across six sites, 713 zero dose and dropout children were newly identified, of whom 595 (83%) were vaccinated. The initiative supported 1093 home visits and strengthened monitoring for 581 routine immunization sessions. Participatory rapid assessments identified nine unmapped micro-areas that were subsequently added to health system microplans. Migrant-dense pockets showed persistent follow-up challenges, primarily due to household mobility and irregular availability.

CONCLUSIONS:
Community-led micro-area engagement, combined with rapid assessment and household-level mobilization, substantially improved the detection and vaccination of previously missed children in underserved urban areas. Sustaining these gains requires consistent field presence, strengthened digital tracking of mobile families, and tailored counselling strategies for migrant communities.