International audienceThe reemergence of plague in the world, the appearance of antibiotic-resistant strains and the risk that genetically modified Y. pestis could serve as a bioterrorist weapon have fostered a renewed interest for vaccination. Currently, researchers mainly follow two distinct vaccinal strategies: one is the development of acellular sub-unit vaccines based on two recombinant targets (F1 and V), and the other is the development of improved live vaccines. Live plague vaccines have been previously largely used in humans and their efficiency against bubonic plague is not disputed. Rather, critics pointed to a limited duration of protection, an unverified protection against pneumonic plague, instability of vaccine seed strain characteristics and the fact that vaccination could induce severe local and systemic reactions. New live vaccine candidates should combine both the known advantages of replicating vaccines: humoral and cell-mediated immune responses, robustness against mutant microorganisms, easiness of mass production and use, limited cost, etc. whilst providing guarantees in terms of security, stability and efficiency against pneumonic plague. They are based not only on attenuated Y. pestis strains, but also on other Yersiniae and live vectors (Salmonella, viruses) expressing Y. pestis antigens. Vaccines against enteropathogenic Yersiniae are also developed
