Healthy Canadians are being asked to wait at least two weeks before receiving the H1N1 influenza vaccine, even though the federal health regulator has given it the stamp of approval and trucks have started rolling out of warehouses carrying the drugs.
That's because there's only a limited amount of vaccine in the initial shipments and local health authorities will give priority to high-risk groups, including pregnant women, adults with chronic conditions and people living in remote places, when vaccination clinics begin next week.
Health officials assured Canadians on Wednesday that there will be enough vaccine for all who need and want it. But with the second wave of the H1N1 pandemic virus already here, it remains unclear if many will be vaccinated too late.
British Columbia, Alberta and the Northwest Territories are seeing widespread H1N1 activity. Ontario, too, is seeing more of the disease, which has infected hundreds of thousands worldwide and killed 4,700, including 83 Canadians.
Perry Kendall, B.C.'s health officer, said healthy people may feel a sense of urgency to jump the queue. But he asked that they wait their turn. The province has received more than 200,000 doses of the 2 million sent across the country in the first shipment.
"We'll be asking other people to hold back. I think we can trust British Columbians and Canadians to understand the importance of reaching the most vulnerable," Dr. Kendall said Wednesday.
The province will roll out the swine flu vaccine on Monday to pregnant women, people under 65 with chronic conditions and those in remote communities. It will be offered to young children, those who care for infants and health-care workers the following week. By the second week of November, all can step up to be vaccinated.
A similar phased-in approach is being applied in other parts of the country.
Gerry Predy, Alberta's senior medical officer of health, said shipments from Canada's vaccine manufacturer, GlaxoSmithKline, are arriving weekly.
"We will vaccinate whoever shows up. But we are encouraging people who are the highest risk to come forward first," Dr. Predy said.
The swine-flu bug, which mysteriously appeared more than six months ago, has once again established a foothold in the northern hemisphere.
Other countries, including the United States, China and Britain, have begun their vaccination programs to prevent further spread of the virus.
Health Canada's much-anticipated vaccine authorization came Wednesday . Local public health districts have been planning mass vaccination clinics and hiring more staff in preparation for the country's largest immunization campaign.
Federal health officials assured Canadians that the vaccine is safe. It confers more than 90-per-cent immunity in healthy adults, said Canada's chief public health officer, David Butler-Jones. "If enough people get immunized it will be very difficult for this virus to take hold and to spread," he said.
There has been some fear about the adjuvant in Canada's vaccine. Adjuvants, which are chemical products that boost the immune response, have not been used in influenza vaccines in Canada. But components of the vaccine have been proved safe: The adjuvant has been tested on thousands with the H5N1 avian flu drug, and the antigen has been tested in other trials in the United States and elsewhere.
Elwyn Griffiths, head of the section of Health Canada that regulates vaccines, said the regulator was satisfied with the results of thousands of clinical trials. One dose is enough for adults. Children six months to 9 years will receive two half doses, administered 21 days apart.
"Our methodology has been thorough and Canadians can have full confidence in the vaccine. We firmly believe that citizens should take advantage of the opportunity to protect themselves and members of their families from this virus," Dr. Griffiths said. "I certainly will."