Asian Scientist (Mar. 3, 2014) – An international team of scientists has identified a novel vaccine strategy against lyssaviruses that cause rabies in animals and humans.
There are 15 known species of lyssaviruses, including Australian bat lyssavirus and rabies virus, which are commonly transmitted by bats or dogs through bites or scratches. Infected animals and humans, if not treated rapidly with a series of injections of inactivated vaccines and expensive immunoglobulins, die in 100 per cent of cases. This is the highest fatality rate for any known infectious disease and over 60,000 people worldwide die from rabies following lyssavirus infections every year.
In their study, published in the Journal of Infectious Diseases, the scientists from Australia, Japan, and France developed a mutated lyssavirus that cannot evade immune responses in the body, resulting in a weakened strain that is switched from a 100 per cent lethal pathogen to one that no longer causes disease in infected mice.
“The production of this new viral strain is a great first step towards making new live rabies vaccines in the future,” said Dr Greg Moseley from Monash University.
“Live vaccines can be grown easily in large quantities, and delivered as a single oral dose, unlike existing ‘killed’ rabies vaccines that must be injected several times over an extended period, limiting their application in resource-poor countries.”
In their study, the researchers identified the region in a lyssavirus protein that inhibits immune responses.
“By making only two specific changes to the approximately 12,000 base pair viral genome, we have rendered the virus non-pathogenic,” said lead author Linda Wiltzer.
“We now plan to develop a candidate vaccine based on our attenuated virus, and test its safety and efficacy in mice.”
The article can be found at: Wiltzer L et al. (2013) Interaction Of Rabies Virus P-Protein With STAT Proteins Is Critical To Lethal Rabies Disease.
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Source: Monash University; Photo: smalltownguy22/Flickr/CC.
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