The Last Mile: Addressing India's Immunization Gap with Zero-Dose Insights from WUENIC Estimates

The global Immunization Agenda 2030, endorsed by the World Health Assembly in 2020, calls for a concentrated push to reach zero-dose children in all countries. The increase in the number of zero-dose children illustrates how layered vulnerabilities originating from social, environmental, workforce-related, and digital systems can interact to undermine even well-established immunization programs. In 2023, 14.5 million children globally missed out on basic vaccines, wherein India contributed nearly 1.6 million to this total. The objective of this narrative review is to synthesize WUENIC and NFHS data to explore trends, factors, and interventions to inform policy. Results shows that India has already reduced its zero-dose children by 27% from 1992 to 2021, however WUENIC estimates reported a 2% increase in the number of zero-dose children in 2023 from 2022. Factors such as socioeconomic and environmental determinants, workforce fatigue lead to negative impact on Immunization programme. Recent WUENIC 2024 estimates reported a coverage recovery with 43% reduction in the number of zero-dose children from 2023 which offers vital insights about India’s resilient health care system. Interventions beyond traditional catch-up drives such as equity-focused microplanning, climate-resilient infrastructure, empowered frontline workers, interoperable digital health systems are having an ability to further address a zero-dose children burden in India. Identifying and vaccinating zero-dose children is crucial not just for lowering under-five mortality, as this group accounts for approximately half of all vaccine-preventable mortality in low- and middle-income countries.