New Rabies Vaccine May Require Only a Single Shot…Not Six
A
person, usually a child, dies of rabies every 20 minutes. However, only
one inoculation may be all it takes for rabies vaccination, according
to new research published in the Journal of Infectious Diseases by researchers at the Jefferson Vaccine Center.
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, according to James McGettigan,
Ph.D., 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,” Dr. 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, according to Dr. McGettigan.
In addition, the vaccine appears to be efficient in both pre-exposure
and post-exposure settings.
Currently,
the World Health Organization standard for rabies infection is
post-exposure prophylaxis. The complex regimen in the United States
requires six different shots over 28 days: five of the rabies vaccine
and one of rabies immunoglobulin.
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.
Worldwide,
the annual number of rabies-related deaths is estimated to be 40,000 to
70,000. The disease is endemic in developing areas, where the six-shot
post-exposure regimen is not feasible for many people due to cost and
availability. According to the World Health Organization, approximately
10 million people worldwide receive the post-exposure regimen, which
presents a financial burden to both industrialized and developing
countries.
“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.”
Dr. McGettigan recently was awarded a four-year $1.5 million R01 grant from the National Institutes of Health to continue
his research on novel rabies vaccine approaches.
Media Only Contact:
Emily Shafer
Thomas Jefferson University Hospital
Phone: (215) 955-6300
Published: 9/21/2009