As provinces and territories get ready to roll out their annual flu-shot programs, new research reinforces the idea that vaccinating little kids could significantly reduce hospital visits during flu season.
The study compared emergency-department visits to children's hospitals in Boston and Montreal before and after the United States adopted a policy of recommending flu shots for kids aged two to five years old.
Emergency-room visits for flu-like illness – as a percentage of total emergency-room visits for kids of this age group – had tracked pretty closely at the two hospitals in the years before the policy shift. But after the change went into effect in the 2006-07 flu season, researchers found a 34-per-cent decline in the rate of emergency visits for flu symptoms at Children's Hospital Boston when compared to the rate at Montreal Children's Hospital.
"It's pretty substantial," lead author Anne Hoen said of the effect found by the study, published in the Canadian Medical Association Journal.
"It means a lot of kids are being protected and staying out of the emergency department due to influenza. And I think it's great evidence that getting your flu shot is a good way to protect yourself and also reduce illness in the community."
The team used the Montreal hospital for comparison because Quebec did not recommend flu shots for children aged two to five at the time. (In fact, it still doesn't – while Canada's National Advisory Committee on Immunization made a recommendation for the 2010-11 season that children aged two to four get vaccinated against flu, to date not all provinces have adopted the recommendation.) Quebec provides free flu shots for children aged six to 23 months. (Children under six months aren't vaccinated against flu.)
In reality, the authors cannot say for sure that the difference they saw was due to flu shots. This type of study cannot offer proof that an effect seen was caused by the intervention being examined; it can only suggest a relationship.
As well, the researchers didn't have breakdowns on what percentage of children in each city got flu vaccine in the years studied.
And U.S. national data suggest early in the life of the new policy plenty of American parents were not heeding the advice to get their children vaccinated against flu. Data for the 2008-09 flu season that were published by the U.S. Centers for Disease Control suggested only 32 per cent of kids aged two to four and 21 per cent of children aged five through 17 got a flu shot that year.
Still, senior author John Brownstein – a Montreal native who along with Dr. Hoen works at Children's Hospital Boston – said the team analyzed the data in such a way to try to rule out other factors that might have accounted for the finding, including differences in the severity of the flu seasons in the two locales.
"It's really mind-blowing. And we had trouble processing that finding as well," Dr. Brownstein admitted. He said they tried "every which way" to disprove the effect, but "nothing could take away that finding."
The study also suggests the benefits of giving flu shots to kids in this age group may extend beyond the kids vaccinated. There were also smaller declines in emergency-room visits for children aged five to nine and 10 to 18 when the Boston hospital's numbers were compared with those of the Montreal Children's Hospital.
Neither of the older groups of children was covered by a flu-shot recommendation at the time in the United States. But it is widely believed small children play a key role in introducing and spreading flu within households, because they are more susceptible to it. The declines among older children may reflect the fact that with fewer little kids getting severely ill, their older siblings might have stayed healthier too.
The study comes as provinces and territories are getting set to begin the annual task of vaccinating against the flu.
Each jurisdiction has its own program, so start dates vary across the country, from the first of October in Ontario to early November in Quebec.
All provinces offer free shots to at least a proportion of their residents – people deemed to be at the highest risk of getting severely ill if they contract the flu.
And an increasing number of provinces and territories are offering free flu shots to all. Where Ontario's universal flu-shot program was a first for Canada – and the world – in 2000, now Alberta, Saskatchewan, Manitoba, Nova Scotia, Yukon, Nunavut and the Northwest Territories all provide flu shots for free for any resident over the age of six months.
The Canadian Press
Flu-shot programs across Canada
Wondering when flu shots will be available this fall? Here's a look at when provinces and territories expect to start offering vaccine, how they'll do it and who is entitled to a free shot.
Alberta Rollout to be announced the first week in October. Shots available for free to any Albertan over six months old.
British Columbia Mid-October, through public clinics, family doctors and some pharmacies. Free for people 65 and older, and their caregivers; children and adults with chronic health conditions and their household contacts; health-care and emergency-response workers; kids between six and 23 months plus household contacts and caregivers of kids under age two; women who will be in the third trimester of pregnancy during flu season; residents of long-term care facilities; aboriginal people; people who are very obese; prison guards and inmates; owners and operators of poultry farms.
Manitoba Details of the program to be announced in early October. Availability expected to follow shortly thereafter. Program is expected to be similar to last year's, which was free to everyone over six months old.
New Brunswick No information available.
Newfoundland and Labrador Expected to start in mid-October. Available through health clinics and doctors' offices. Free to adults and children with chronic conditions; people in residential care and workers looking after them; people aged 60 and older; children six to 23 months; health-care workers; essential-service workers; First Nations people; pregnant women; poultry and swine workers; people living in households with people who are at high risk of complications from flu.
Northwest Territories Date, details have not yet been fixed, though generally the first or second week of October. Free to all over six months old.
Nova Scotia Mid-October. Available through doctors' offices, some public-health and workplace clinics. Free to everyone over six months old.
Nunavut Date not yet fixed, though the territory is aiming for the third week in October. Vaccine is distributed through clinics and health centres. Free to everyone over six months of age.
Ontario Oct. 1. Available through clinics, doctors' offices and workplace clinics. Free to everyone over six months old.
Prince Edward Island Start date has not yet been announced. Available through long-term care facilities and hospitals; public-health clinics and family doctors. Free to people in long-term care or in hospitals; health-care workers; pregnant women and children aged six to 23 months. Some health centres and family physicians may charge an administration fee for giving the vaccine.
Quebec Nov. 1. Available through doctors' offices, and through the government's centres de santé et de services sociaux (CSSS). Free for adults 60 and over; pregnant women in their second and third trimesters; children six to 23 months; the chronically ill; people living or working with kids under six months of age or other people at high risk; health-care workers.
Saskatchewan Oct. 11. Available through flu-shot clinics, public-health offices and doctors' offices. Free to everyone over six months old.
Yukon Oct. 24 for the general public, Oct. 17 for people in long-term care. Offered through flu-shot clinics manned by community-health nurses. Free to everyone over six months of age.
The Canadian Press