Every year about this time I have a dream where I wake up and the flu has been eradicated. It hasn’t come true yet. And so every year, like millions of other Canadians, I trek to get my annual influenza vaccine. But millions more do not, and 5 to 10 percent of adults in this country continue to get sick with the disease every year.

Most healthy people who get sick with the flu will recover in one to two weeks, but the economic impact of missed work and hospital visits is still substantial. And for some, especially those over 60 and those with chronic conditions, complications from the flu can be severe and even life-threatening. “Influenza is the most common infectious disease cause of death in Canada,” says Dr. Allison McGeer, Director of Infection Control at Mount Sinai Hospital in Toronto.

The good news is that most provinces and territories provide the vaccine free to all residents six months of age and older, with the exceptions being Quebec, British Columbia, and New Brunswick, all of which offer the vaccine only to those at high risk. And yet, despite this, many Canadians are still opting not to receive immunization.

Concerns about safety and efficacy

Many people are concerned about the effectiveness of the flu shot, especially after last year’s vaccine failed to protect against the strain that ended up being most prevalent in Canada. Historically, though, the flu vaccine is about 50 to 60 percent effective, meaning that vaccinated people lower their risk of getting influenza by about half compared to unvaccinated people. “The measurement is not whether a vaccine works all the time,” reminds Dr. McGeer. “The measurement is whether it’s better to take it or not to take it, in terms of how likely you are to get sick and how serious the illness will be. On that scale, there is no question about the efficacy of the flu vaccine. Years and years of data and research have shown that.”

"The effectiveness of last year's vaccine doesn't predict this year's."

Some people also believe that the influenza vaccine can itself cause the flu. “The vaccine does not result in the flu,” says Dr. Bryna Warshawsky, Public Health Physician at Public Health Ontario. “The most common side effect is a sore arm. Still, a lot of the time people think they got the flu afterwards because they have caught one of the other viruses that are circulating at the same time.”

It’s equally important to remember that there are many different strains of influenza and new ones are evolving all the time. Each year, the flu vaccine is formulated in an attempt to target the three or four strains expected to be most prevalent in the upcoming flu season. “The effectiveness of last year’s vaccine doesn’t predict this year’s,” says Dr. Warshawsky. “The viruses change frequently and the composition of the vaccine changes every year to try to match them.”

The dream of one vaccine for a hundred flus

As for my dream of wiping out the flu, it’s not quite as far-fetched as you might imagine. It’s years away at best, but scientists are working hard in an attempt to develop a broad spectrum permanent influenza vaccine. “That’s the holy grail of influenza vaccines,” says Dr. McGeer. “Just recently there have been some reports on a mouse influenza vaccine that’s much more broad spectrum. That’s a long way from a human vaccine, but there is a lot of development work going into it.”

Until that time, it’s off to the clinic for me, not just to protect myself, but also to protect those at higher risk who I may come in contact with. Hopefully, more Canadians than in years past will be doing the same.