One inoculation may be all it takes for rabies vaccination instead of the series of shots that carries the image of being a painful ordeal, according to new research.
A replication-deficient rabies virus vaccine that lacks a key gene called the matrix (M) gene induced a rapid and efficient anti-rabies immune response in mice and non-human primates, said James McGettigan, assistant professor of Microbiology and Immunology at Jefferson Medical College of Thomas Jefferson University.
“The M gene is one of the central genes of the rabies virus, and its absence inhibits the virus from completing its life cycle,” McGettigan said. “The virus in the vaccine infects cells and induces an immune response, but the virus is deficient in spreading.”
The immune response induced with this process is so substantial that only one inoculation may be sufficient enough, McGettigan said. The vaccine appears to be efficient in both pre-exposure and post-exposure settings, he said.
The complex regimen in the United States requires six different shots over 28 days: five of the rabies vaccine and one of rabies immunoglobulin.
Worldwide, the annual number of rabies-related deaths is estimated to be 40,000 to 70,000, and most are children.
The disease is endemic in developing areas, where the six-shot post-exposure regimen is not feasible for many people because of cost and availability. About 10 million people worldwide receive the post-exposure regimen, which presents a financial burden to both industrialized and developing countries, according to the World Health Organization.
“Developing countries do not have the resources to vaccinate people six times after exposure, so many of these 10 million do not receive the full regimen,” Dr. McGettigan said. “ Therefore, simpler and less expensive vaccine regimens are needed. The alternative may also be to treat people pre-exposure, as they are with many of the current vaccines used. Although our vaccine was tested primarily to be a post-exposure vaccine, the data we collected show it would be effective as a pre-exposure vaccine as well.”