Plague, caused by a rod-shaped bacterium called Yersinia pestis, no longer invokes the "black death" feared throughout history, having been widely tamed since the advent of antibiotics. But a new concern has emerged in recent years with respect to bioterrorism.
"There have been discovered some resistant strains to antibiotics and that poses a concern, especially if plague would be used as a bioweapon," said Luca Santi, a research assistant professor at the institute and lead author of the study published in the early online edition of the journal Proceedings of the National Academy of Sciences. "A new vaccine approach would be the best way to prevent infection."
In addition to manmade threats, the Centers for Disease Control estimates 1,000 to 3,000 outbreaks still occur in the world every year as a result of people coming into close contact with rodents infected with fleas that harbor the bacteria.
Particularly worrisome to human health is the pneumonic form of the disease, which can spread by an airborne route after infecting the lungs. It is considered universally fatal if not detected and treated after symptoms arise one to six days after the initial exposure.
Current vaccines against plague are severely limited from widespread adoption by having problems with high adverse reaction rates and side effects.
The research team included Santi, Hugh Mason and Charles Arntzen, all members of the institute's Center for Infectious Disease and Vaccinology. They worked out a new plant-based system to rapidly and
Source:Arizona State University