Community structure in host networks is not limited to human networks: Animal populations are often divided into subpopulations, connected by limited migration only [44, 45] . Targeted immunization of individuals connecting subpopulations has been shown to be an effective low-coverage immunization strategy for the conservation of endangered species [46] . Under the assumption of homogenous mixing, the elimination of a disease requires an immunization coverage of at least 1-1/R 0 [1] but such coverage is often difficult or even impossible to achieve due to limited vaccine supply, logistical challenges or ethical concerns. In the case of wildlife animals, high vaccination coverage is also problematic as vaccination interventions can be associated with substantial risks. Little is known about the contact network structure in humans, let alone in wildlife, and progress should therefore be made on the development of immunization strategies that can deal with the absence of such data. Stochastic algorithms such as the acquaintance method and the CBF method are first important steps in addressing the problem, but the large difference in efficacy between stochastic and deterministic algorithms demonstrates that there is still a long way to go.