In these exclusive interviews, we speak to Dr. Julio Frenk (Dean of the Harvard School of Public Health, and former Minister of Health of Mexico), Sir Richard Thompson (President of the Royal College of Physicians), Baron Peter Piot (Director of the London School of Hygiene and Tropical Medicine) and Dame Sally Davies (The United Kingdom’s Chief Medical Officer). We talk about the concept of public health, the most important health challenges the world currently faces, and opportunities for the future.