The manner in which limited vaccines are distributed during a pandemic is an ethical issue. The utility principle has been used to argue priority be given to certain individuals based on factors such as the epidemiology of the spread of disease and maintaining the functioning of society. The equity principle has been used to encourage fair practices that account for the economic and social costs of all decisions made. We argue that both principles are met through priority vaccination of homeless individuals, as this strategy protects a medically vulnerable population while reducing the chances of transmission to others as they move through populated urban spaces. We begin by reviewing debates around ethical vaccine distribution. We then argue the homeless are a medically high-risk population who may contribute to the spread of disease through their mobility. As immunization rates are generally lower among the homeless and many do not access mainstream health care, we argue that community vaccine clinics must be used to reach these individuals. We provide support by analyzing Toronto Public Health’s operation of vaccine clinics in shelters and drop-in centres during pH1N1 and conclude that this strategy is effective for immunizing homeless individuals, bringing together the equity and utility principles.