Vaccination clinics across Canada started offering the vaccine in the fall of 2009. (Jeff McIntosh/Canadian Press)

About four in 10 Canadians rolled up their sleeves for the H1N1 shot last flu season, Statistics Canada says.

Based on self-reported data, nearly six out of 10 Canadians, or 16.5 million people aged 12 and over, did not get vaccinated against the H1N1 virus, the agency said Thursday.

The new influenza strain emerged in April 2009 and most people had no natural immunity to it. Vaccination clinics across Canada started offering the vaccine in the fall of 2009.

Of those who did not get the shot, the most common reason, given by 74 per cent, was that they "did not think it was necessary."

The second most common reason, reported by 13 per cent, was that they "had not gotten around to it yet." The third most common reason, reported by seven per cent, was fear, but the nature of the fear was not given.

"It is interesting to look at why Canadians didn't get vaccinated," said report author Heather Gilmour, a researcher with Statistics Canada's health analysis division in Ottawa.

"Many people didn't think that they needed it, and that might help us understand how public health education campaigns could improve in the case of another pandemic."

Priority groups

Rates of vaccination were higher for specific risk populations, especially among groups given priority for early immunization.

For example, 66 per cent of health-care workers said they had an H1N1 shot, compared with 35 per cent of the rest of the population.

Similarly, 55 per cent of Canadians with chronic conditions, which placed them at increased risk for complications, received the vaccine. The chronic conditions included in the report were heart disease, diabetes, asthma, chronic obstructive pulmonary disease, Alzheimer's disease or dementia, and obesity.

In comparison, 38 per cent of those without chronic conditions were vaccinated.

Newfoundland and Labrador had the highest vaccination rate at 69 per cent and Ontario had the lowest at 32 per cent. The territories were excluded.

"The lowest vaccination rates was in Ontario," said Dr. Michael Gardam, an infectious diseases specialist and the medical director of infection prevention and control at Toronto's University Health Network.

"This is quite surprising because it is the only province that has had a universal vaccination campaign for almost a decade. One would have thought that vaccination would have rolled out smoother there."

The percentage of Canadians vaccinated for H1N1 exceeded the percentage who typically get a seasonal flu shot: 32 per cent.

In the U.S., adults were more likely to have been vaccinated against seasonal flu (39 per cent) than H1N1 flu (20 per cent) during last year's flu season, Statistics Canada said.

About 76 per cent of Canadians who had received the seasonal flu shot within the last year also opted for the H1N1 vaccine, compared with 28 per cent who had never received a seasonal flu shot.

Patricia Ariss, 24, of Edmonton caught the swine flu virus last October and took two months to fully recover. Ariss doesn't plan on getting the flu shot this year.

"I guess I need to be convinced that I need it before I get it," said Ariss.

In Canada, 428 people died from H1N1, and thousands were infected, according to the Public Health Agency of Canada.

This week, a Senate committee started a review of Canada's pandemic response to gauge what could be done differently.

The World Health Organization declared the pandemic over in August.