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GSK Calls New Bird Flu Vaccine More Effective
 
 
  NY Times
By DENISE GRADY
Published: July 27, 2006
 
A new vaccine against bird flu developed by GlaxoSmithKline is more effective than any previous version and works at a far smaller dose, the company reported yesterday on its Web site.
 
The ability to immunize people with small doses greatly increases the possibility of making enough vaccine to protect much of the population in the event of a pandemic.
 
Until now, high dosage requirements have been a major obstacle to making a vaccine for avian flu. An earlier vaccine, made a year ago by Sanofi Pasteur and stockpiled by the government, required such large doses that it would be difficult or impossible to keep up with a pandemic.
 
GlaxoSmithKline said it had tested its vaccine in Belgium in 400 healthy people, ages 18 to 60, who were then given blood tests to measure their immune systems' response. The tests showed that more than 80 percent of the subjects were protected by two shots, each containing only 3.8 micrograms of an antigen, an immunity-stimulating substance made from the bird flu virus.
 
By contrast, the first Sanofi vaccine protected only about 50 percent of the test subjects, who received two shots with much higher doses, 90 micrograms each.
 
But health officials said it was too early to make any recommendations about how and when the vaccine should be used if it reached the market. And it is not clear that the vaccine would still be effective if the virus mutated.
 
The GlaxoSmithKline vaccine is not yet available, but the company expects to seek approval for it this year from the Food and Drug Administration and from drug agencies in other countries. A spokesman for the F.D.A., Paul Richards, said, "We are encouraged by GSK's promising report," and added that the vaccine would probably qualify for an accelerated approval process that could be completed in six months. The vaccine will sell for the same price as a standard flu shot, said Patty Seif, a GlaxoSmithKline spokeswoman. Worldwide, that cost for consumers averages $8 to $12 a shot, she said.
 
What sets the new product apart is that it includes an adjuvant, a substance added to stir up the immune system and make the vaccine work better and at lower doses. Alum is a common adjuvant, but it did not provide enough enhancement with bird flu vaccine when tested by Sanofi.
 
The nature of GlaxoSmithKline's adjuvant is a trade secret, but David Stout, president for worldwide pharmaceuticals at the company, said the ingredients had already been given to people in other products, though not in this particular combination.
 
"How we mix and match is what's proprietary," he said.
 
Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, said GlaxoSmithKline's findings were "very, very impressive." But he cautioned that the results were based only on blood tests, not real-life exposure.
 
"The proof of the pudding is, how does it work in the field," he said, adding that it would be especially important to find out if the vaccine still worked if the bird flu virus began to change genetically. It is too early, he said, to tell what the government's plans might be for buying and stockpiling this vaccine.
 
Dr. David Nabarro, chief pandemic flu coordinator for the United Nations, said: "Certainly this is welcome, but we've only had a press release. It's very difficult for any of us to comment in more than general terms."
 
Dr. Irwin Redlener, head of the National Center for Disaster Preparedness at Columbia University, said, "This is very promising technology, but what is still not known is how well this vaccine will work on whatever the actual strain is that produces a pandemic."
 
Even so, he said, it would make sense for the government to stockpile about 40 million doses of the GlaxoSmithKline product and start using it if a pandemic began. If the vaccine worked, more could be made; if it did not, crash production of another vaccine would be needed.
 
Flu pandemics occur when people encounter new viral strains to which they have no immunity. The bird flu virus now spreading around the world, known as A(H5N1), is such a strain, but so far it has not managed to spread easily to people or between them. If it were to mutate in a way that made it more contagious among people, a deadly pandemic could erupt.
 
But, Dr. Nabarro warned, yet another new virus, totally unrelated to A(H5N1), could pop up, and in that case the current vaccines will be useless. The A(H5N1) virus could also mutate enough to make the vaccines obsolete, he said.
 
"We're a long way away from seeing this vaccine being part of the pandemic preparedness strategy for governments, but it's welcome news and likely to be a step in the right direction," he said.
 
Mr. Stout said the company had not yet met with government officials in any country to make plans for the use of the vaccine.
 
He said that GlaxoSmithKline's current production capacity for seasonal flu vaccine was 60 million to 70 million doses a year, and that it could make an equal amount of the bird flu vaccine. By 2008, it expects to be able to make 150 million doses a year. But those amounts can vary considerably.
 
The A(H5N1) virus has spread rapidly through birds in Asia, Europe and Africa in the last few years. The virus attacks mainly birds, but some humans have been infected, mostly through contact with birds. So far, the disease has been highly lethal in people, killing more than half its victims. It seems rarely to spread from person to person, but that could change.
 
Since 2003, 232 people in 10 countries have contracted bird flu, and 134 have died. The worst current outbreak is in Indonesia.
 
While Glaxo's vaccine offers protection against the deadly H5N1 avian flu virus now circulating, its impact on any mutated strain of virus is not certain.
 
However, experts say it could ``prime'' a person's immune system so they will get stronger effects from a later, better-matched vaccine.
 
Glaxo said it would now also study the ability of its vaccine to offer cross-protection to variants of the H5N1 virus.
 
$2 BILLION SALES?
 
Deutsche Bank analysts said an H5N1 vaccine could have sales potential of $2 billion a year, which would add 3-5 percent to Glaxo's long-term earnings.
 
Dresdner Kleinwort said an effective vaccine could be a slight negative for Roche Holding AG, since it might reduce demand for its Tamiflu flu drug.
 
The H5N1 strain of avian influenza has spread rapidly out of Asia and has killed more than 130 people who have come into close contact with infected birds.
 
Experts fear it could trigger a pandemic, a global epidemic of flu that could kill millions, if it acquires the ability to pass easily from human to human.
 
Companies are racing to develop pandemic H5N1 vaccines that could save lives and buy time to develop a vaccine against a pandemic strain. It could take from four to six months from the start of a pandemic before a specific vaccine will be ready.
 
Other firms working on a bird flu vaccine include Novartis AG and Baxter International Inc.
 
 
 
 
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