TORONTO – The season of coughing, sneezing, sick days and flu shots is here.
Each winter, Canadians make their way to flu vaccination clinics to arm themselves against the season’s wave of influenza that typically arrives in October or November and lingers until March. And those of us who don’t get the flu shot test our odds to see if we’ll catch the bug that spreads wildly, peaking around January.
Last year, influenza crept into the country and left without much fanfare but Canadian doctors say that this winter, the flu season will be average, meaning that it will leave its mark on parts of the country.
“This year, the predicted strains of the influenza seem to be fairly typical and we are expecting an average flu season,” Dr. Paul Das, a St. Michael’s Hospital family physician, told Global News.
That means the flu virus should make an appearance by November, and by January, an upswing of sickness should hit the country and linger for about four weeks before influenza dies down, according to Dr. Gerald Evans.
Evans is a Queen’s University medicine professor and chief of infectious diseases at Kingston General Hospital.
“There really isn’t anything at the moment that has us worried, like new strains of pandemic flu,” he said. He doesn’t anticipate a pandemic such H1N1 which triggered an epidemic in 2009.
Strains of influenza that could make their way to Canada this year
There are three types of influenza: A, B and C.
Influenza A is the “big bad one we always worry about,” Evans says, while he calls influenza C “inconsequential.”
Influenza B, for its part, is an important disease in that it hits kids more so than adults. Each year, the flu vaccine administered to patients contains protection against two strains of influenza A and one strain of influenza B.
This year, North American doctors are bracing for a strain of H1N1 called A/California/7/2009, a H3N2 strain called A/Victoria/361/2011 and an influenza B similar to a B/Wisconsin/1/2010.
Each year, strains of the influenzas mutate and re-emerge infecting victims and triggering a new season. Those of us in the northern hemisphere keep a watchful eye over the flu in the southern hemisphere, which affects residents during their winter or our summer.
Scientists look at the patterns and garner their predictions based on what viruses made their rounds below us and estimate what mutations could occur before the influenzas make their way over the equator.
They narrow their guesses to only a handful and those three strains are then included in the seasonal vaccine that’s given to the masses.
Evans says that three-quarters of the time, the medical community is right, and the flu vaccine concocted that year is the correct defense against that year’s influenza.
Influenza typically begins on the West Coast
Flu illnesses are more common during the winter, or between October and March in the northern hemisphere, and April through to September in the southern hemisphere, Das explains.
He says data from national influenza surveillances show that infections typically peak earlier in Western Canada – which is in January – than Eastern provinces, which are usually hit by late February.
Evans says his guess is that the West Coast is typically a point of entry for people travelling to and from Asia, which is where most influenzas first appear.
“There’s a lot more people who travel to the southern hemisphere, for instance, or over to Asia and so when those strains begin circulating it’s those travellers who are returning to Canada that gets the seasonal strain moving,” he said.
“I notice each year that when you look at the maps that show activity, it very often seems to be that it starts on the West Coast and moves across Canada to the east side,” he said.
Once it’s dug some roots into a community, those roots spread, Evans explained.
He lives in Kingston, Ont. with a population of about 200,000 people.
He says 20 to 30 per cent of the population would become infected if influenza made its way into the community.
While the vast majority of people who get the flu recover, others who are either young or old or have underlying medical conditions will end up with lingering health issues.
“When influenza hits a community, we see a jump in the number of hospitalizations for things like pneumonia, heart failure or heart disease,” Evans says.
Vaccination is key to protecting against the flu
Both physicians – along with the rest of the medical community – are advising Canadians to get their flu shots to help protect themselves, and the people around them from catching influenza.
At this point, Evans says that vaccination rates nationally sit at a meagre 20 to 25 per cent while health care workers report higher numbers at about 40 per cent.
During H1N1, vaccination rates increased from coast to coast, though – that year, about 50 per cent of the country got their flu shots.
But that wasn’t the case in Ontario, Das says.
The province’s universal influenza immunization program saw flu shot uptake drop in 2009 from about 40 per cent to 25 per cent.
And that same year, as flu shot uptake declined, flu cases doubled and the number of deaths from influenza complications quadrupled.
Evans says that if at least 75 per cent of the public were to be immunized, “herd immunity” would occur. That means that even if a single person wasn’t vaccinated, if most of the people around them were, the risk of transmission would be very low.
He cautions that while most of us feel healthy, the flu shot has benefits that extend beyond our own immune systems.
“I’m a doctor and I get my shot every year so the likelihood of me getting the flu is reduced, and that means I’m unlikely to transmit to my family, my friends and to my patients that I see,” he said.
“It’s one of those things where it’s good for you, but it’s also good for everybody around you too.”
Kids as young as six months old can start getting the vaccine.
It’s also recommended for populations at risk of complications. These people who are more vulnerable include pregnant women, children under five years old, seniors and residents in long-term care or nursing homes.
Das also says that those with underlying health problems, such as chronic diseases (asthma, chronic bronchitis, cancer) should also make their way to a flu vaccination clinic.
The physicians also suggest that getting the vaccine earlier helps. It takes about two weeks for the vaccine to be most effective, and its effects are long-lasting.
For more on the flu season, take a look at the government’s Flu Watch.
To read about flu prevention tips, take a look at the Public Health Agency of Canada’s website.
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