Bruce Gellin is president of global immunization at the Sabin Vaccine Institute. He previously served as the deputy assistant secretary for health and director of the National Vaccine Program Office at the US Department of Health and Human Services, where he was the principal advisor to the assistant secretary for health on vaccine and immunization programs and policies. Gellin also represented HHS as a technical and policy advisor to the World Health Organization, with a focus on influenza and vaccine hesitancy and as a contributor to the Decade of Vaccines Collaboration and the Global Action Vaccine Action Plan. Prior to that, he worked at the CDC and NIH.