Jefferson scientists create safer rabies vaccine

This development was enabled by the unexpected discovery that a tiny change in a rabies virus protein can turn a “safe” virus extremely deadly. Scientists at Jefferson Medical College 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.

“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,” said Dr Bernhard Dietzschold, professor of microbiology and immunology at Jefferson Medical College. “As a result, we think we have engineered a virus which is nonpathogenic and extremely stable.”

Wildlife rabies is a substantial health problem in the US. It is particularly prevalent along the East Coast, where more than 90% of reported cases occur in wildlife. In the US alone, more than $1 billion is spent annually for control, treatment and prevention of rabies.

Dr Dietzschold explains that the current wildlife rabies vaccine used in the US is ineffective in a chief carrier: skunks. The vaccine developed by his team is much broader, showing efficacy in such animals as raccoon, skunk and mongoose. One of the problems with current vaccines is the fact that several varieties are used, depending on the particular species of animal. The scientists hope their vaccine will prove useful for rabies prevention in several species.

The researchers are asking for permission from the US Department of Agriculture and the Environmental Protection Agency to perform field trials. These would entail placing food baits containing the vaccine in the wild, then later capturing and testing animals for antibodies against the rabies virus.