As Canada considers having all residents roll up their sleeves for flu shots, public-health experts will meet at the World Health Organization in Geneva Thursday to prepare a plan to vaccinate the world's population against a pandemic influenza strain.
WHO executive director David Heymann said yesterday that he hopes international health officials, including those from Health Canada, will walk away from the table with ideas to boost the number of vaccines that can be produced and delivered worldwide in a single year.
"The concern is that there is only the capacity in the world to develop 260 million doses of vaccine ..... 260 million in a world of how many billion?" said Dr. Heymann, who was in Toronto for a conference on the global battle against infectious disease.
"If there's a pandemic influenza, there would be a need to vaccinate as many people as possible; you'd have to go into developing countries and industrialized countries alike.
"If you're looking at vaccine needs, they're incalculable."
A flu pandemic, which could cause widespread global infection, as did the 1918 pandemic that killed more than 20 million people, is expected to emerge within five years.
No flu vaccine protects against such a strain, which experts predict would evolve from a bird-flu virus, jump the species barrier into humans, then develop the frightening power to spread among people.
The most likely viral candidate is the persistent and virulent so-called H5N1 avian flu spreading in Asia among various animal species and humans.
The European Union is sending a team of medical experts to Asia this month to investigate the situation.
First identified when it struck chickens in China in 1997, the H5N1 virus is causing an epidemic among chickens in Asia, where more than 100 million have been culled in an effort to contain the disease.
But the virus, which seems to spread through migratory birds, has gone on to infect ducks, domestic cats, possibly pigs and 20 tigers in Thailand.
Forty-four human cases with 32 deaths have been reported, 20 in Vietnam and 12 in Thailand.
News reports from Thailand said yesterday that three more people are thought to have contracted the virus after having close contact with chickens that died of unknown causes. Two of these patients are one and six years old.
"It is finding human hosts, and there is one possible or probable transmission of human-to-human contact a mother who was possibly infected by her child who lived in Bangkok," Dr. Heymann said.
Two vaccines for the H5N1 Asian bird flu are in development and expected to be tested in clinical trials early next year.
But Frank Plummer, scientific director of the National Microbiology Laboratory in Winnipeg, who also spoke at yesterday's conference, cautioned that "it is a gamble" to invest too many resources in developing vaccines for the H5N1 avian flu.
"It's the most likely bet right now, but we just don't know what could happen," Dr. Plummer said.
But the bird flu has caused considerable distress among the Asian populations.
Poultry industries have been devastated and people are trying to contain panic.
Although there are no official reports of bird flu in China, the discovery of tainted feathers from infected birds intended for stuffing in winter coats sparked the fear of contaminated clothing.
And the Thai News Service reported yesterday that a motorist sped off from a traffic light, fearing bird-flu contamination when four pigeons, near death, fell onto the road.
Allison McGeer, an infectious-diseases expert at Toronto's Mount Sinai Hospital, who spoke yesterday about a worldwide pandemic to a conference organized by St. Michael's Hospital and the University of Toronto, noted that the Asian bird flu has triggered so much concern because it appears to be evolving rapidly, has an apparent mortality rate of 70 per cent and the world is well due.
"Thirty to 40 years is the longest gap between pandemics in the last 400 years," Dr. McGeer said.
But, she cautioned, no one knows whether the speedy changes to the H5N1 virus are typical of a precursor pandemic strain because no scientists have, until now, kept such close watch of flu activity in the microbial world.