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World’s best vaccine against hepatitis B
An Israeli company offers the most effective solution against a virus that affects at least two billion people across the world.
18.12.2013
Since 1982, developing countries have been vaccinating newborns against the hepatitis B virus (HBV). Yet this leading cause of life-threatening liver infection remains a major global health problem directly affecting some two billion people and many more as silent carriers.
Why? Solving this riddle is what enabled the scientists at Israel’s SciGen to pioneer the world’s only commercially available third-generation vaccine against the virus that causes 1.2 million deaths every year.
SciGen CEO Michal Ben-Attar explains that Sci-B-Vac is the most effective and cost-efficient solution to combating HBV anywhere, and is especially needed in Africa where the rates of infection are high.
Almost every newborn in Israel already receives this cutting-edge inoculation on the day of birth, and the formula is registered for use also in Hong Kong, the Philippines, India, Vietnam, Georgia and Central Africa, with approvals in the United States and other countries expected in the near future.
Ben-Attar is eager to partner with a major pharmaceutical company so the company can offer the same unprecedented protection to infants in other countries.
Close to nature
Sci-B-Vac was based on advanced biotechnology to eliminate the problems inherent in first-generation and second-generation HBV vaccines, she explains.
“The point of biotechnology is to simulate natural processes as closely as possible,” she says.
“Other vaccines, like for smallpox and polio, were so effective that after decades of use, the diseases virtually vanished. But hepatitis B, after 30 years, is still found all over the world in large percentages. We understand the reason and therefore developed the third-generation vaccine.”
The first generation of HBV vaccines used an isolated form of the virus from infected people. The health risks involved made this solution unappealing from the start, and already in 1992 scientists began working on a second-generation vaccine using a yeast-derived, genetically engineered version of the virus’s main protein.
“They hoped the antibody made in response to this protein would be enough to stop the infection, but actually it’s not effective enough,” says Ben-Attar. People with a variety of health conditions, from gluten intolerance to diabetes, do not respond to the vaccine.
About 15 years ago, two physicians from the Weizmann Institute of Science in Rehovot attended an international conference of HBV researchers. They came away determined to find a way to produce a vaccine made of recombinant proteins mimicking the three that make up the native virus.
A year later, the Israeli doctors presented their solution: an HBV lookalike that is actually a hollow envelope containing three proteins derived from mammal cells. When it is injected, the body produces protective antibodies against all three of these proteins, offering unprecedented effectiveness.
Safe and effective
Ben-Attar says that only purified proteins made from a line of mammalian cells (in this case, hamsters) are similar enough to the human native virus. They were successfully tested for safety in 5,000 people.
In addition, a recent study at Hadassah University Medical Center in Jerusalem looked at the effectiveness of Sci-B-Vac in newborns infected with the virus from their mothers. It takes 60 days for the disease to develop, and the vaccine halted the progression in every case.
Among the general newborn populations, the use of Sci-B-Vac has significantly reduced HBV incidences in Israel since it was introduced in 2005. It is the only vaccine given on the day of birth because of the great danger of infection. Ben-Attar explains that HBV is up to 100 times more infectious than HIV, as the virus lives outside the body for more than 10 days.
“I would like to see everyone protected with our vaccine, but for a start we are targeting non-responders,” says Ben-Attar, a biologist. “In Israel, the Ministry of Health says to use only our product if there is high risk.”
Though about 80 Israeli companies are currently developing recombinant proteins for vaccines, she adds, SciGen possesses the most advanced methods to synthesize it. The company shares its knowledge and manufacturing facilities with startup companies that need these materials for clinical studies.
The privately owned company, established in 2005, has 50 employees. Ben-Attar hopes that future profits can be re-invested in the company to advance its research and development of inoculations for AIDS, Alzheimer's and other debilitating diseases.
By Avigayil Kadesh
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发表于 2013-12-24 08:37