For decades, the flu vaccine has been the same general recipe: a needle filled with three strains of inactivated virus meant to ward off the real thing.
Now, for the first time for Canadians, a fourth strain of virus is being added with the hope of making the publicly available vaccine even more effective.
It’s called a four-strain, quadrivalent (QIV) vaccine.
“It’s sort of like building a better mouse trap,” Mark Loeb, division director, infectious diseases, McMaster University told Global News. “If you have a vaccine that will capture both these strains, it’s no longer a guessing game as to whether the vaccine will have activity against B; both lineages of B will be covered.”
“It’s a bonus.”
Flu vaccines have been trivalent (TIV) with three-strains — two influenza A-strains and one B-strain — for decades.
READ MORE: Virus mutations: Here’s why scientists say last year’s flu vaccine was a bust
Last year, there was a mutation in an A-strain. In addition, there was a mismatch for the one B-strain. So this year, by offering two B-strains the Public Health Agency of Canada (PHAC) is hoping more influenza will be prevented by the vaccine. “The potential benefit is expected to be greater among children who tend to have a higher burden of influenza related B disease,” the PHAC wrote in an email.
“We’re hoping for a better match this year,” Perry Kendall, British Columbia’s provincial health officer told Global News.
“It is estimated that between 10-20 per cent of the population becomes infected with influenza each year. Rates of influenza infection are highest in children aged 5–9 years, but rates of serious illness and death are highest in children aged under 2 years old, persons older than 65, and persons with underlying medical conditions,” according to the PHAC.
Last year, Canada experienced one of its deadliest flu seasons in decades: 606 people died and there were more than 8,000 hospitalizations, according to PHAC.
Not all Canadians are eligible for the new four-strain vaccine
However, not all Canadians will have access to the four-strain vaccine. That decision is up to the provinces and territories. According to PHAC, “approximately 12 million influenza vaccine doses have been ordered by provinces and territories this year for their public immunization programs. Of this total, approximately 2.9 million doses will be four-strain vaccines.”
In British Columbia the four-strain QIV vaccine is just for children 19 and under, in Ontario for children 6 months to 17 years old, and in Alberta the four-strain QIV vaccine will be provided to children.
In Quebec and Saskatchewan it will be for infants 6 months up to 23 months, and if needed it can be administered to children 2 to 17 years old with compromised immune systems and those considered vulnerable and high risk.
However, in Manitoba, Yukon, Nunavut, Nova Scotia, Prince Edward Island and New Brunswick the four-strain vaccine QIV will be administered to all ages – adults and children. In the Northwest Territories it will be given to everyone under 65. In Newfoundland and Labrador the four-strain vaccine is available for all ages, but residents over 65 living in long-term care will receive the trivalent.
Provinces have the option of offering the vaccine as an injection or as a nasal spray.
“The flu nasal spray is a good option for children who don’t like getting needles, and it provides broader protection by protecting against four strains of the flu,” said Eric Hoskins, a physician and Ontario’s health minister. “We want to make it as easy and convenient as possible for parents to protect their kids.”
The four-strain vaccine costs more, and some provinces are waiting for reviews on the effectiveness in adults before providing it for all residents. The health agencies also told Global News children are more vulnerable to B-strain flu infections.
Physicians and health officials are urging Canadians to get a flu shot, and want to reinforce that the three-strain vaccine (TIV) is effective.
“Even when there is a mismatch there is benefit,” said Loeb.
“The vaccine is always going to help you in any given flu season,” said Doug Sider, Ontario Public Health’s medical director of communicable disease, prevention and control.
In addition to getting a flu shot, Sider said people can reduce their risk of becoming sick by washing their hands frequently, disinfecting shared or regularly touched surfaces and practicing what he called “respiratory etiquette” — sneezing and coughing into your sleeve.
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