 As we have already noted, financial resources are always limited in public health. There is never enough money in the public health sector to pursue all the policies and practices that could advance population health. Although arguably a redistribution of resources among competing public sectors, for example from a country’s defense budget to its health budget, may be ethically warranted and could relieve some of the more pressing constraints, tough priority setting and allocation decisions are a constant feature of policymaking in public health and are likely ineliminable. There are also occasions in public health, however, when money is not the primary constraint and questions of just distribution can take on somewhat different features. Sometimes referred to as cases of absolute scarcity or of extreme rationing, an urgently needed intervention is in short supply, and the supply problem cannot be fixed in real-time simply by allocating more money to the  problem.[7]  A classic example is countermeasures for epidemic diseases, where production of the countermeasure, typically a vaccine, lags behind the need. In these cases, standard debates between efficiency and various alternative distributive principles can take on new twists or are augmented by appeals to somewhat different principles. For example, when epidemic vaccines are in short supply many judge that health professionals and other first responders should enjoy high priority for receiving a vaccine. The rationale for this position appeals to a mix of utilitarian and non-utilitarian reasons. Some see the relevant distributive principle to be a combination of contribution and reciprocity; because these people are putting themselves at increased risk of acquiring the infection, literally putting their lives on the line for others, first responders are entitled to special consideration in access to preventive interventions. At the same time, the argument is also made that the public health system needs these experts to be both willing and able to perform their duties and thus that it is important to use guaranteed access to a scarce vaccine to both incentivize first responders to work on the public’s behalf and to keep them healthy.