Despite the fact that influenza vaccine is an important health resource, the structure and organization of the US vaccine manufacturing system has produced influenza vaccine shortages or distribution delays in five out of the last six influenza seasons. These shortages have produced the need for local public health officials to develop protocols for rationing and redistributing influenza vaccine at the local community level. In so doing, local health officials are confronted with significant practical and legal constraints associated with allocating a resource that is largely not under direct government control. In the face of an impending influenza vaccine shortage, local public health departments endeavor to do three things: (1) assess the local supply of vaccine, (2) assess the local demand from high-risk community members, and (3) ensure that to the greatest extent, the limited local supply of vaccine is used exclusively by those at highest risk within the local jurisdiction. There are a number of legal tools and strategies that local health officials have at their disposal to carry out these functions. This article will attempt to outline some of the significant legal impediments and practical constraints that local public health officials face in managing influenza vaccine supply-demand issues and will offer some suggestions for strengthening their ability to effectively manage these increasingly common situations.