Canadians who chose not to be immunized against H1N1 during the pandemic will have another shot at getting protected with this year's seasonal flu vaccination.
Next week, provinces and territories will begin rolling out the 2010-11 vaccine, which includes H1N1 A and two other strains - H3N2 influenza A Perth and influenza B Brisbane.
There has been some early influenza activity in Canada. In Southern Ontario, for instance, two long-term care residences and one school had recent outbreaks of H3N2.
All children over six months and adults of all ages are encouraged to get a flu shot, said Patricia Huston, senior medical adviser for the Public Health Agency of Canada.
"It will protect you against the pandemic H1N1 strain, for example," Dr. Huston said. "But we anticipate it will be a new H3N2 strain that will be circulating this year, so previous flu vaccines will not cover you for that."
"Even if you've had the H1N1 vaccine, so you say, 'Why should I get it again?' … there is no harm in having a repeat vaccine or a booster, and it will protect you for the new strains that may be coming out."
A recent Statistics Canada survey found only about four in 10 Canadians aged 12 and older - or about 11.6 million people - rolled up their sleeves for an H1N1 shot last season. .
For this season, the Public Health Agency has ordered 11.2 million doses of the vaccine from manufacturers GlaxoSmithKline and Sanofi Pasteur, based on requests from the provinces and territories. Total cost of the bulk order: about $40-million to $45-million.
Provinces and territories began shipping vaccine to health units last month. Distribution to clinics, long-term care facilities and doctors' offices is already under way.
While this year's vaccine won't be offered on a priority basis to high-risk groups, public health officials are stressing those vulnerable to complications should get their shots as soon as possible.
The National Advisory Committee on Immunization has lengthened its list of those considered at high risk for complications from flu - including the elderly, young children and people with underlying health conditions. Close contacts of high-risk groups and of health-care and essential-service providers are also urged to bare their arms for a shot.
This year, NACI has added three other groups it considers at elevated risk: those who are morbidly obese, with a BMI of 40 or higher; aboriginals, who were found to be more susceptible during the H1N1 pandemic; and healthy children aged two to four.
Dr. David Williams, Ontario's associate chief medical officer of health, agreed that "predicting the flu season is worse than predicting the weather."
But the province's theme for this flu season is "getting back to business" after the pandemic, he said.
Ontario has purchased five million doses and all residents are eligible for a free flu shot under the universal influenza immunization program.