Vivian Welch contributes to global health in her role as co-convenor of the Campbell and Cochrane Equity Methods group where she leads methodological development on how to assess whether research applies to vulnerable populations, often excluded from primary research studies. She led an influential Campbell systematic review relevant to global health focused on mass deworming for children in low- and middle-income countries. Vivian has contributed to other influential Campbell and Cochrane systematic reviews on school and preschool feeding, which have informed World Food Programme policies. Since 2017 Vivian has been Editor in Chief of the Campbell Collaboration, which aims to provide better evidence for a better world, with a focus on informing global social policies.