Novel Hepatitis C Vaccine Shows Some Early Promise

WEDNESDAY, Jan. 4 (HealthDay News) — A vaccine to protect
against the hepatitis C virus, which can cause severe liver damage and
even liver cancer, might be possible — but it’s likely years away,
researchers are reporting.

There is currently no vaccine for hepatitis C, which afflicts an
estimated 170 million people worldwide.

Like HIV, the hepatitis C virus mutates easily and has always been
considered a difficult pathogen to immunize against because it’s
constantly changing. However, preliminary research by British and Italian
scientists suggests that the virus might one day be beatable due to a
novel approach.

The researchers treated 41 healthy volunteers with a vaccine designed
to generate a response by T cells (infection-fighting cells) against the
virus’ internal proteins, instead of aiming to create an antibody attack
on the ever-changing outer coat of the virus. Study lead author Dr. Paul
Klenerman, a senior research fellow at Oxford University’s Nuffield
Department of Clinical Medicine, said the new vaccine is based on research
by a biotech company in Italy. The researchers are calling it the first
clinical trial of a hepatitis C vaccine in humans.

The inside of the virus is much more stable than its outer coat,
Klenerman explained, and it’s also headquarters for “crucial pieces of
machinery.” He said the researchers used a chimpanzee-based adenovirus
(similar to the common cold virus) as a method of vaccine transmission,
and were able to prime a large cellular immune response against hepatitis
C that lasted for a year — the length of the study.

But many questions remain to be answered, Klenerman said. “At the
moment the trial is just Phase 1 and it looked at safety and an
appropriate dose. It needs to go through at least a Phase 2 trial to show
whether it’s protective. That trial would probably take two or three
years,” he said.

Klenerman added that even if the researchers do develop a safe,
effective vaccine, it’s not certain whether it would protect against
different strains of hepatitis C.

“This vaccine is based around one particular genotype — or strain. The
virus itself is very variable. So there’s a chance that even if it works
well against one strain, it could be less effective against other strains.
Viral variation is really a big challenge,” he said.

The study is published in the Jan. 4 issue of Science Translational
Medicine
.

Commenting on the trial, Dr. Andrew Muir, director of gastroenterology
and hepatology research at the Duke Clinical Research Institute, said:
“It’s a novel approach toward a vaccine we’ve never had much enthusiasm
for. We’d been told it’s unlikely there would be a hepatitis C
vaccine.”

Muir said that, while many questions remain, if a hepatitis C vaccine
were developed, it would be a boon. “Treatment is incredibly expensive,”
he said, with the current cost ranging from about $50,000 to $100,000.

Dr. Bruce Bacon, professor of internal medicine in the division of
gastroenterology and hepatology at St. Louis University School of
Medicine, said the payoff from such a vaccine is likely years away. “It’s
early yet and a lot has to be done to prove efficacy. If you can develop a
vaccine that’s effective, you can significantly reduce the burden of
disease, but maybe the burden of disease 20 years from now.”

Prevention and screening efforts, and developing effective medications
may be more practical areas of focus for now, Bacon said.

People are risk of hepatitis C infection include those on long-term
kidney dialysis; have regular contact with blood at work (such as
health-care workers); and those who use injectable street drugs, according
to the U.S. National Institutes of Health.

More information

To learn more about hepatitis C, visit the U.S. National Digestive Diseases
Information Clearinghouse
.

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