During the period July–December 2024, JSI, as the Zero-Dose Learning Hub global learning partner, continued to provide technical assistance and collaborate and co-create with the Nigeria Learning Hub, led by the African Field Epidemiology Network (AFENET) and the Africa Health Budget Network (AHBN). This semiannual update for the Gavi, the Vaccine Alliance Board and other stakeholders highlights the Learning Hub’s efforts to leverage evidence for a deeper understanding of the factors that affect the implementation and performance of strategies to identify and reach zero-dose and under-immunized children and missed communities in Nigeria. Key efforts included implementation research on national strategies such as the Zero-Dose Reduction Operational Plan (Z-DROP) and Identify, Enumerate, and Vaccinate (IEV); expansion of the Decentralized Immunization Monitoring (DIM) approach across four states; and facility-level data quality assessments to support improved monitoring and planning. This report synthesizes findings, challenges, and recommendations emerging across the IRMMA framework.