Researchers say that a single shot of vaccine might soon be efficient enough to provide protection against rabies.
The team led by Dr James McGettigan, assistant professor of Microbiology and Immunology at Jefferson Medical College of Thomas Jefferson University showed that 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.
"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," he added.
The immune response induced with this process is so substantial that only one inoculation may be sufficient enough to provide protection.
The current standard vaccine is made from inactivated rabies virus, whereas the experimental vaccine is made from a live rabies virus.
The virus is modified by removing the M gene, thus inhibiting its spread within the vaccine recipient.
"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," said McGettigan.
"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," he added.
The study appears in Journal of Infectious Diseases.