Strengthening Routine Immunization and Vaccine Equity (STRIVE) in the Democratic Republic of the Congo and Brazil - The program, Strengthening Routine Immunization and Vaccine Equity (STRIVE) in the Democratic Republic of the Congo (DRC) and Brazil, will bolster national and subnational immunization systems by implementing innovative approaches to 1) achieve high, sustainable, and equitable immunization coverage rates among target populations; 2) control, eliminate, and eradicate vaccine-preventable diseases (VPDs); and 3) decrease VPD-related mortality and morbidity. STRIVE will build upon its 100+ year combined history in strengthening routine vaccination programs spanning 26 provinces and 516 health zones in the DRC to enhance national and subnational immunization systems. The STRIVE program will focus on co-designing solutions to foster government ownership, deploying embedded project staff within the National Immunization Program and Health Zones to streamline immunization service delivery, promote a collaborative capacity building approach, and ensure the program’s long-term sustainability. Coordinately closely with the Ministry of Health and local partners, STRIVE aims to improve data quality and management through enhanced interoperability, GIS applications, workforce training, and the culture of data demand and use. The program employs a dynamic approach to programming, encompassing community-engaged surveillance, social behavior change (SBC), and empowering faith and community leaders to become local-level influencers to improve demand for vaccines and reduce hesitancy. Through evidence-based methods and co-designed approaches, STRIVE will strengthen an equitable immunization system that meets national quality standards and engages stakeholders at all levels for effective delivery—ultimately curtailing mortality and morbidity related to VPDs. In Brazil, STRIVE will leverage 85 years of collective in-country immunization experience to enhance the National Immunization Program by strengthening the cascade of national guidance, policies, and resources to State and Municipal Health Departments in alignment with Brazil’s decentralized model of health services. The program will drive positive improvements in immunization and surveillance at the state and municipality levels by adapting national tools and guidance to address local-level needs; strengthening health department capacity to implement behavioral design analyses and interventions for vaccine hesitancy; improving the digital literacy among frontline healthcare workers; supporting onboarding of municipalities to standard government data systems; and engaging local influencers to build community-level trust in vaccines. STRIVE’s contextual understanding, data driven approaches, and collaboration with the National Immunization Program and its partners will advance immunization services to the unimmunized and under-immunized populations to control, eliminate, and eradicate VPDs.