 Public health’s population focus also positions it well to lead on the prevention of disease and injury (Rose 1985, Rose et al. 2008; Childress et al. 2002; Faden, Shebaya, and Siegel 2019). Although clinicians often incorporate preventive interventions in their practice with patients, no other social institution is generally recognized as so clearly having a prevention remit. Many public health agencies, including in the US the Centers for Disease Control and Prevention and the FDA’s Center for Food Safety and Nutrition are designed to prevent illness and injury at the population level. Public health’s commitment to prevention carries with it particular moral challenges. Eliminating or mitigating harm that already exists is sometimes viewed as being of greater moral importance – or simply as more immediately motivating action – than long-term strategies to prevent harm from materializing. Whether it is ethically justifiable to privilege the interests of the currently ill, who are often known and identifiable, over those of future people who cannot now be identified is a paradigmatic challenge of justice in public health ethics addressed briefly in Section 2.