WHO South East Asia Region reviews progress of Big Catch Up Initiative, charts path for sustained immunization recovery

The WHO South‑East Asia Regional Office (WHO‑SEARO) convened the Big Catch‑Up (BCU) Implementation Review Workshop from 10–12 December 2025 in New Delhi, bringing together national and subnational immunization managers, technical experts, and WHO staff from Nepal, Myanmar, India, and Timor‑Leste, alongside WHO staff from the regional office and headquarters. Key partners—including UNICEF, Gavi, the Vaccine Alliance, the Program for Appropriate Technology in Health (PATH), John Snow India (JSI), and the Immunization Technical Support Unit (ITSU)—joined the workshop to jointly review BCU progress and shape strategies for institutionalizing catch‑up vaccination.

The workshop highlighted significant recovery since the BCU initiative launched in 2023 to address immunity gaps widened by COVID‑19. Countries reported meaningful reductions in zero‑dose children, improved antigen coverage, and increasing integration of catch‑up into routine systems. India’s progress stood out, with a 43% reduction in zero‑dose children and strong antigen‑specific gains supported by digital platforms such as U‑WIN.

Throughout the workshop, country teams exchanged lessons on addressing persistent routine immunization gaps, leveraging digital tools for tracking and monitoring, and tailoring strategies for urban, mobile, and hard‑to‑reach populations. Field visits in Delhi provided participants with practical exposure to service delivery models, community engagement approaches, and local innovations that are helping to strengthen coverage.

Technical sessions from WHO and partners reinforced these discussions. WHO emphasized critical data gaps and the need for stronger digital systems to sustain routine catch‑up. WHO Headquarters provided global insights, noting that while the BCU initiative improved planning, monitoring, and stakeholder engagement, countries must now transition from campaign‑style activities to fully institutionalized routine systems.

Partners presented complementary perspectives. Gavi outlined its 6.0 strategy to streamline funding, improve data systems, and scale innovations. UNICEF presented regional insights and case studies from Nepal and Myanmar, underscoring the role of community engagement, behavioral insights, and strengthened cold‑chain and delivery systems in improving equity and sustaining routine immunization.

India’s Delhi team demonstrated how targeted microplanning, U‑WIN‑enabled tracking, and focused outreach helped reduce zero‑dose children in complex urban settings. PATH showcased a range of innovations—from cold‑chain technologies to human‑centered design and digital tools—that can improve access for underserved populations. ITSU highlighted the need for stronger urban‑focused planning, enhanced microplanning, and data‑driven, community‑centered delivery approaches. JSI emphasized the importance of localization through community‑based organizations and hyper‑local communication to improve vaccination uptake and equity.

Despite progress, participants acknowledged ongoing challenges, including coverage inequities, data quality issues, resource constraints, and workforce limitations. Countries identified key priorities: developing country‑owned workplans, strengthening real‑time data systems, sustaining partner engagement, and prioritizing approaches for vulnerable and underserved populations.

Closing the workshop, Dr Suman Rijal, Director for Department of Communicable Diseases, underscored the need to embed catch‑up vaccination as a routine, continuous component of immunization programmes. He emphasized prioritizing vulnerable groups, smarter resource allocation, stronger community engagement, and accelerated digitalization to sustain gains. He reaffirmed WHO’s commitment to continued collaboration and cross‑country learning to ensure no child is left behind.

The BCU workshop served as a critical regional platform to consolidate evidence, share practical solutions, and reinforce collective commitment to institutionalizing catch‑up vaccination across the region.