U of A researchers move closer to discovering hepatitis vaccine
By Jodie Sinnema, edmontonjournal.com
John Law, research associate, is part of a team that has made a significant discovery in the search for a vaccine against hepatitis C at the University Hospital in Edmonton, Feb. 15, 2012.
EDMONTON - A University of Alberta research team is one step closer to discovering a vaccine for hepatitis C that appears to work against all the major strains of the disease.
Michael Houghton, a researcher at the Li Ka Shing Institute of Virology at the U of A, says his discovery was unexpected. That’s because there are six major strains of hepatitis C and hundreds more subtypes infecting 170 million people around the world. Hepatitis C is spread through contaminated blood and can be associated with needle-sharing, medical procedures involving unsterilized equipment, or blood transfusions.
Vaccines, made with the antibodies of specific strains, tend to only work against those specific disease types. Think, for instance, about the flu vaccine and how it covers only certain strains expected to circulate during a given flu season.
Houghton said new data from the U of A shows his vaccine, made from one strain of the hepatitis disease, produces antibodies that can neutralize all the hepatitis C types around the world.
“I think that’s great news for our efforts to develop a vaccine for hepatitis C,” said Houghton, a world-renowned expert in medical microbiology and immunology who discovered the hepatitis C virus in 1989. He presented his recent findings during Wednesday’s Canada Excellence Research Chairs Summit in Vancouver. “It’s a very unexpected result and it’s guiding us toward the development of a successful hepatitis vaccine.”
Such a vaccine was thought impossible and impractical, since hepatitis C is more heterogeneous — or has more varieties — than HIV.
“In the HIV field, for example, it’s been the Holy Grail for many years to try to elicit antibodies that can neutralize all the different types around the world,” Houghton said. He, then, has potentially discovered the Holy Grail for hepatitis C.
“I think it’s a very big step forward,” he said. “I’ve been working on the vaccine for 15 years (and) for so many years, the field felt that antibodies would be very restricted in their neutralizing ability, that you could only neutralize the same strain that the vaccine was derived from.”
His lab study defied that belief.
“It’s very encouraging that we can do it and really gives us a hope that an effective vaccine can be produced for hep C.”
John Law, Houghton’s research partner, said preliminary tests showed the vaccine blocked some strains from entering a person better than others, with success rates ranging from 40 per cent to 100 per cent. He said the effectiveness could be improved in clinical trials by playing with the dosage.
Houghton said while it would take five to seven years before such a vaccine could hit the market — it must be proven safe and effective in large clinical trials involving humans — he said the vaccine could also help those already infected with the disease. Of the millions who carry the infection, up to 20 per cent develop chronic illness, including cirrhosis of the liver.
A drug cocktail already on the market cures 70 per cent of those infected with hepatitis C, Houghton said. He said further research needs to determine if a combination of that antiviral with the new vaccine could increase the success rate.
“It may also be beneficial as a therapeutic vaccine,” he said. “That does deserve attention in the future.”
Dr. Lorne Tyrrell, a hepatitis expert and the Canadian Institutes of Health Research and GlaxoSmithKline chair in virology at the U of A, said if the vaccine proves effective, it will have a global impact. In Egypt, for instance, 10 per cent of the population carries hepatitis C.
“In many parts of the world, the antiviral therapy we currently have for hepatitis C is often out of the reach of most people’s affordability so having a (cheaper) vaccine that could be used to prevent the disease in those countries is particularly important,” Tyrrell said.
“There’s still a lot of work that needs to be done, but at least it’s a clue and an indication that we can develop a potential vaccine for hepatitis C.”
© Copyright (c) The Edmonton Journal
Source
Click Here To View Video
CTV Edmonton: Major Hepatitis C discovery
Click Here To View Video
CTV Edmonton's health reporter Carmen Leibel talks to a U of A researcher who may have discovered the world first Hepatitis C vaccine.
No comments:
Post a Comment