Posted on 08/09/2005 12:37:37 AM PDT by ex-Texan
TORONTO (CP) - Enthusiasm over the news that U.S. researchers have proven a vaccine is effective against the H5N1 avian flu strain was tempered Monday with word that it took massive doses - roughly 12 times the normal amount - to produce a protective response in humans.
Given that manufacturers can only make enough vaccine for a fraction of the world's population in normal times with regular dosing schedules, experts said the findings underscore the urgent need to find ways to produce the same response with smaller doses of vaccine.
"I think these results suggest the world is even less prepared than more prepared," said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
"And unfortunately many policy makers might take this announcement as being 'We've hit the gold mine' - when in fact I would suggest we are having a hard time even finding water."
In light of the American findings, federal officials said studies into a yet-to-be-made Canadian H5N1 vaccine will key in on the role antigen-sparing techniques could play in pandemic vaccine production. (Antigen is the substance in vaccine that provokes the immune system to produce protective antibodies.)
"It's something that we are definitely considering in the design because of what we (now) know," said Dr. Theresa Tam, associate director of respiratory diseases at the Public Health Agency of Canada.
"It's of great interest to us to look at these types of antigen-sparing strategies, whether it be adjuvants or whole viruses."
Adjuvants are chemicals that, when mixed with vaccine, kick the body's immune response up several notches, allowing a smaller dose of vaccine to produce a bigger effect. Vaccines made of whole viruses, rather than viral particles, are known to provoke greater immune responses as well but are also known to produce more side-effects on administration.
It is hoped the Canadian studies will begin late next summer. February's federal budget set aside $34 million for production of trial batches of an H5N1 vaccine. But Canada's flu vaccine manufacturer, ID Biomedical, still has not been given the go-ahead to do the work.
"We're close to entering into a contract. Hopefully it will be done shortly," Health Minister Ujjal Dosanjh said Monday.
The company has said it would take 12 months from contract signing to vaccine delivery, because it must build and license a special high-biosecurity facility within its existing vaccine plant.
The U.S. teams found it took two doses of 90 micrograms each to induce the immune system to churn out good levels of neutralizing antibodies, the immune system warriors that protect against invaders. The primer and booster shots were given 28 days apart.
"We know that neutralizing antibodies should predict protection," said Dr. John Treanor, head of the vaccine trials group at the University of Rochester (N.Y.), one of three teams involved in the study.
*Ping* !
If the Canadians do manage to produce this vaccine in quantity, the facility will go on strike just as the epidemic strikes, and all available vaccine will be reserved for Liberal politicians.
It's common knowledge that politicians are hoarding available treatments at present, while begging the proles NOT to hoard, "have some consideration of your neighbours".
Thanks for including me on your ping list. I wondered just how effective the vaccine would be, now I have my answer!
Tamiflu Spares Mice From Lethal Avian Flu Strain
Please also note that I'm not a hack or representative of Hoffman La Roche Pharmaceuticals.
I can't be too revealing regarding the "whys" and "how comes"; but if you want to be proactive in protecting yourself from the Avian flu...this would be the route that I'd go. Comes in 10 dose blister-packs. FYI
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