The worldwide supply of a pandemic influenza vaccine will take twice as long to manufacture and countries could have barely half of what they need for the fall's flu season if current production problems persist, the World Health Organization revealed Monday.
Canadian health authorities admitted that not everyone will receive the vaccine at the start of the flu season, as they scrambled to prioritize which groups would move to the head of the queue. Pharmaceutical manufacturer GlaxoSmithKline Inc. is under contract to produce enough vaccine for all Canadians who wish to receive it, but it's unclear how quickly the vaccine will be rolled out and even if most will be vaccinated in the event the virus returns with a vengeance this fall.
Still, Canada and other affluent countries are better off having lined up manufacturers and purchased the bulk of the vaccine. The WHO urged wealthier nations to hand over vital pandemic influenza vaccines to poorer nations - a tall order in the face of dwindling supplies.
The federal government said it is considering the WHO's request, but health authorities stressed that Canadians would get first priority.
The vaccines may not come all at once and we can't vaccinate everybody at the same time Theresa Tam, Public Health Agency of Canada
Fear of a limited supply was sparked Monday after the WHO revealed that the race to produce an H1N1 vaccine has achieved "poor" results because the new virus strain is not growing fast enough in the eggs used as a mainstay of flu vaccine production. Manufacturers report that the swine flu strains being used are barely producing half as much yield to make vaccines as the seasonal flu virus. If the problem persists, the vaccine wouldn't be immediately available for everyone.
The WHO said laboratories are generating new seed strains for manufacturers, and hoped the problem could be worked out in the coming weeks.
But Theresa Tam, the director-general of infectious disease and emergency preparedness for the Public Health Agency of Canada, said it was prudent to determine who will get the first doses. The agency hadn't been in touch with GlaxoSmithKline on the amount of vaccine that will likely be available to Canadians, nor a timeline. There is an understanding that at least some of the drug will be available by early November.
"The vaccines may not come all at once and we can't vaccinate everybody at the same time," Dr. Tam said.
Because a vaccine could be late in arriving, Dr. Tam said it may be necessary to roll out the vaccination program after just the initial clinical trials, which would require health officials to be diligent in collecting data on safety and effectiveness.
Health professionals and others who are key to the country's critical infrastructure are likely to get first access to any vaccine. The job of deciding who's next is in the hands of a vaccine working group as well as a special committee of provincial and territorial chief medical officers of health and their advisers, Dr. Tam said.
Canada's pandemic plan states that maintaining critical infrastructure such as health-care services and reducing deaths and severe illness are primary objectives. So that will be taken into consideration when the lists are finally drawn. But so will the way the disease is affecting the population.
Pregnant women, those with chronic health conditions, young children and healthy adults have been hard hit by the pandemic virus. The latest victim was a 25-year-old, otherwise-healthy, Calgary mother who caught the flu while visiting family in Saskatoon last month. A funeral was held Monday for Vanessa Bluebell.
"Every pandemic is different and we are seeing, for example, younger people who are being affected rather than people over the age of 65," Dr. Tam said. "I think the prudent thing to do is look at various scenarios in terms of severity and the types of groups that are affected and see how we would prioritize under those circumstances."
GlaxoSmithKline declined to reveal what kind of yield it is seeing in its early work with the new virus. In a statement, it said that the work is continuing and the company "expects to deliver the first vaccine supply … in three or four months time depending on availability of standards from health authorities."
Donald Low, head of microbiology at Toronto's Mount Sinai Hospital, said countries may just have to accept the lower yield, which translates into half as much of the vaccine being developed as the seasonal flu vaccine.
As vaccine makers rush to test new seed strains, Dr. Low said surveillance studies should be conducted in the summer so that health authorities prioritize groups.
"It will be very important to clearly identify who is at greatest risk for this infection, because if we don't have unlimited amounts of the vaccine available, then that means we're going to have to carefully identify individuals," he said.
With a report from The Canadian Press