Abstract
The potential application of Yersinia pestis for bioterrorism emphasizes the urgent need to develop more effective vaccines against airborne infection. The current status of plague vaccines has been reviewed. The present emphasis is on subunit vaccines based on the F1 and LcrV antigens. These provide good protection in animal models but may not protect against F1 strains with modifications to the type III secretion system. The duration of protection against pneumonic infection is also uncertain. Other strategies under investigation include defined live-attenuated vaccines, DNA vaccines, mucosal delivery systems and heterologous immunization. The live-attenuated strain Y. pestis EV NIIEG protects against aerosol challenge in animal models and, with further modification to reduce residual virulence and to optimize respiratory protection, it could provide a shortcut to improved vaccines. The regulatory problems inherent in licensing vaccines for which efficacy data are unavailable and their possible solutions are discussed herein.
Acknowledgements
The authors thank Vladimir L Motin and Yury A Popov for helpful discussions and for continuous encouragement, and Natalya Y Teryoshkina for her assistance in the manuscript preparation.
Financial & competing interests disclosure
The work of Valentina A Feodorova was supported by the Russian Foundation for Basic Research (Grant 03-04-48067) and the BII/ISTC Project #3853. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.