Bridging Gaps in Childhood Immunization Timeliness: Global Evidence from JRF Data with a Spotlight on Nigeria

Abstract

Childhood vaccination remains one of the most effective public health interventions, yet delays and missed opportunities undermine herd immunity and equity. The WHO/UNICEF Joint Reporting Form (JRF) provides a global platform to monitor vaccination timeliness and catch-up doses, offering critical insights into zero-dose populations and equity gaps. Nigeria, as one of the countries with the highest burden of zero-dose children, presents a compelling case for contextual analysis. This study assessed global progress in monitoring timely and catch-up vaccination using JRF data, while highlighting Nigeria as a case study to explore practical barriers and policy solutions for reducing immunity gaps.