Maker Calls New Bird Flu Vaccine More Effective
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
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,
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
“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
Since 2003, 232 people in 10 countries have contracted bird flu, and 134
have died. The worst current outbreak is in Indonesia.