MMGH supported the Wellcome Trust in mapping and sizing the factors influencing vaccine developers’ decisions in progressing along the development pathway: from transition into Phase II clinical trials to early commercialisation. Using a survey and literature review approach, and with the support of an Expert Advisory Group, MMGH identified key challenges where focused interventions could remove barriers and improve the ecosystem for the development of vaccines used in low-income countries, or against diseases of epidemic potential. The output of the work was discussed at the Sabin-Aspen Vaccine Science & Policy Group in September 2020.