"We have identified a molecular mechanism involved in making the rabies virus pathogenic and lethal, and have developed a very safe vaccine for the immunization of wildlife," says Bernhard Dietzschold, DVM, professor of microbiology and immunology at Jefferson Medical College of Thomas Jefferson University in Philadelphia, who led the work. "As a result, we think we have engineered a virus which is nonpathogenic and extremely stable."
Reporting recently in the Journal of Virology, Dr. Dietzschold, Matthias Schnell, Ph.D., associate professor of microbiology and immunology at Jefferson Medical College, and their co-workers identified a mutation in a rabies virus gene that changes a single amino acid in the virus's outer coat. The alteration was enough to turn a "safe" virus into a deadly version, making the virus unusable for vaccination.
Wildlife rabies is a substantial health problem in the United States. It is particularly prevalent along the East Coast, where more than 90 percent of reported cases occur in wildlife. Raccoons are the most affected, with skunks a close second. Worldwide--and especially in underdeveloped nations--rabies takes a large human toll; more than 60,000 deaths a year. In the United States alone, more than $1 billion is spent annually for control, treatment and prevention of rabies.
The Jefferson scientists uncovered the mutation, during the testing of a virus they thought was suitable for use in vaccinating wildlife. The virus is first altered so that it will not cause disease, yet will arouse the immune system's defenses. Because viruses such as rabies have high mutation rates, researchers typically "
Source:Thomas Jefferson University