Are you getting the flu shot this year? Many Canadians will not, even though safe and effective flu vaccines have been available for more than 60 years. In fact, only one-third of Canadians aged 12 and over got a flu vaccination in 2013–2014. And while the consequences of not having a flu vaccine are inconvenient for some — a few days of feeling unwell — they can be devastating for others.
Between 10 and 20 per cent of Canadians are infected with influenza every year, leading to hospitalizations and deaths for at-risk individuals. Although the exact number of hospitalizations and deaths is debated by experts, it is clear that for some, influenza is not a benign illness — and can be deadly.
Seniors are the most significantly affected. They represent 15 per cent of the Canadian population, yet account for up to 40 per cent of influenza infections and the majority of hospitalizations and deaths from influenza.
That’s because seniors are more likely to be frail — 74 per cent of Canadians age 65 or older reported having at least one chronic condition and 25 per cent (more than one million seniors) are medically frail.
For those who are frail, in addition to the immediate effects, influenza infection can be difficult to recover from, leading to progressive loss of function and increased frailty.
But it’s not just older individuals who are at risk.
High rates of flu complications occur in people of any age with chronic medical conditions of the heart, lungs, kidney, liver and blood. Anyone with diabetes or compromised immune systems from, say, cancer treatment, is also at higher risk.
This is the same for pregnant women, where the risk goes up in the second and third trimester, and for children under age two. Indigenous peoples are also high-risk groups, due to higher chronic health conditions among certain populations.
So why not just immunize the vulnerable?
First, paradoxically, for those who are at highest risk of influenza complications, the influenza vaccination might not be as effective as in those who are well, leading to persistent but reduced susceptibility.
Second, the best way to protect the vulnerable from flu is to prevent the spread of influenza. Healthy people can spread the flu before showing signs of illness, and the flu vaccine significantly reduces the spread of influenza in the general population.
That’s why the National Advisory Committee on Immunization says it’s especially important for health-care workers and others in contact with vulnerable people to get the flu vaccine.
How effective is it? That depends.
Unlike other vaccines, the flu shot cannot eradicate influenza altogether since new strains of influenza appear every year.
That is why a new flu shot is made available every year directed against the strains most likely to be present that year — with varying success.
Research continues on developing universal flu vaccines that would be effective against all strains, but we aren’t there yet. However, new high-dose preparations of influenza vaccines have recently become available that are more effective for those at highest risk, such as the elderly.
Yes, antiviral drugs are available for treating the flu, but influenza viruses can develop resistance to these drugs.
Overall, the flu shot will provide reasonable protection against the flu, especially if you get it early in the season. No, it’s not 100 per cent. But if you do get the flu, even though you did get the shot, chances are that you will fare much better.
As for the side-effects, they are low, with the most common adverse effect being pain at the injection site.
And in case you heard the rumour — no, influenza vaccines do not cause the flu.
The fact is, influenza is one of Canada’s top 10 infectious diseases and has a catastrophic impact on the most vulnerable in our society. So get your flu shot for your sake, for your loved ones and your community.
And while you’re at it, make sure your other vaccinations are up to date, too.
John Muscedere is the scientific director and CEO of the Canadian Frailty Network, a not-for-profit organization funded in 2012 by the Government of Canada’s Networks of Centres of Excellence program.
