Yersinia pestis, the bacteria of Black Death infamy, has had the power to strike fear in people since the Middle Ages – and for good reason. Once someone begins to show symptoms, the disease progresses very quickly and is almost 100 percent fatal without prompt treatment.
In addition to having long been identified as a potential bioterrorism agent by U.S. federal government, the World Health Organization has categorized Yersinia pestis as a re-emerging pathogen because of the rising number of human plague cases globally.
Researchers at the University of Texas Medical Branch at Galveston have been hard at work developing new potential vaccines to protect against this deadly pathogen.
By deleting and modifying certain genes, the UTMB researchers constructed new versions of the Y. pestis bacteria designed to provide immunity to the plague without making them ill. They then examined several aspects of the immune response after immunization and tested how long the immunization would protect mice and rats against the plague.
Overall, all three of the new possible vaccines stimulated long-lasting immune responses capable of protecting animals from developing the pneumonic plague as late as four to five months after vaccination.
“The optimal strategy for protecting people and animals against this deadly disease would be through vaccination, but there are no FDA-licensed plague vaccines available in the U.S.,” said Ashok Chopra, UTMB professor of microbiology and immunology. “In addition to how well a vaccine works to protect against disease, safety is another important aspect for vaccine development. We have shown that our mutants are safe vaccine candidates as our detailed analyses showed no sign of damage to bodily tissues in the vaccinated animals.”
Read more at NPJ Vaccines: Immunization of two rodent species with new live-attenuated mutants of Yersinia pestis CO92 induces protective long-term humoral- and cell-mediated immunity against pneumonic plague.
