The Zero-Dose Learning Hub (ZDLH) established by Gavi, the Vaccine Alliance (Gavi), is focused on the outcome of timely, increased, and sustainable use of evidence to improve global, regional, and country immunization programs and policies in alignment with the Gavi 5.0 Strategy and Identify, Reach, Monitor, Measure, and Advocate (IRMMA) Framework. The semiannual update for the Gavi Board and other stakeholders highlights the ZDLH consortium’s efforts to generate and share evidence for a deeper understanding of the factors that affect the implementation and performance of strategies to identify and reach ZD and under-immunized (UI) children and missed communities. It synthesizes findings, challenges, and recommendations across the IRMMA framework emerging from the Learning Hubs. This summary provides brief highlights of the ZDLH's activities as the global learning partner from January-June 2024. See the country reports for a detailed summary of each country’s priorities, activities, progress, and learnings to date.