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Volume 39, Number 2, April 2006

Salmonella-based plague vaccines for bioterrorism

Leona Nicole Calhoun, Young-Min Kwon
Cell and Molecular Biology Program and Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, United States

Received: October 1, 2005       Accepted: December 26, 2005   


Corresponding author:

Dr. Young-Min Kwon, Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas 72701, United States. E-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it




Yersinia pestis, the causative agent of plague, is an emerging threat as a means of bioterrorism. Accordingly, the Working Group on Civilian Biodefense, as well as the Centers for Disease Control and Prevention, has specified Y. pestis as a prime candidate for use in bioterrorism. As the threat of bioterrorism increases, so does the need for an effective vaccine against this potential agent. Experts agree that a stable, non-invasive vaccine would be necessary for the rapid large-scale immunization of a population following a bioterrorism attack. Thus far, live Salmonella-based oral vaccines show the most potential for this purpose. When delivered via a mucosal route, Salmonella-based plague vaccines show the ability to protect against the deadly pneumonic form of plague. Also, mass production, distribution, and administration are easier and less costly for attenuated Salmonella-based plague vaccines than for plague vaccines consisting of purified proteins. Most attenuated Salmonella-based plague vaccines have utilized a plasmid-based expression system to deliver plague antigen(s) to the mucosa. However, these systems are frequently associated with plasmid instability, an increased metabolic burden upon the vaccine strain, and highly undesirable antibiotic resistance genes. The future of Salmonella-based plague vaccines seems to lie in the use of chromosomally encoded plague antigens and the use of in vivo inducible promoters to drive their expression. This method of vaccine development has been proven to greatly increase the retention of foreign genes, and also eliminates the need for antibiotic resistance genes within Salmonella-based vaccines.



Key words:

Bioterrorism, plague vaccine, Salmonella, Yersinia pestis



J Microbiol Immunol Infect 2006;39:92-97.