CALGARY – Three flu outbreaks have been reported in British Columbia this season, and Alberta experts warn it’s a strain that hasn’t responded very well to vaccines so far.
“Often with the H3N2, the effectiveness is very low,” said Dr. Jim Dickinson with the Alberta Flu Surveillance Program. “We’re not very good at getting a vaccine that works against that particular strain.”
Though Alberta Health Services said there haven’t been any influenza outbreaks in the province since Aug. 30, data from the last eight seasons suggests vaccine effectiveness rates between 50 and 60 per cent.
“We’d like to have 100 per cent, perfect vaccine, but even reducing by 50 per cent is worthwhile,” said Dickinson.
One B.C. provincial health officer said the seasonal flu vaccine protection is projected to be as low as 30 per cent.
“Our best guess…from looking at the vaccine effectiveness in the southern hemisphere is that it won’t be as effective as we would really like it to be, which is 70 per cent, but it’ll certainly be better than last year,” said Dr. Perry Kendall. “Some of the estimates that I’ve seen is between 30 per cent and 50 per cent.”
H3N2 is expected to be dominant in Canada, since that’s the only strain seen so far in B.C., but this year’s vaccine is a better match for H1N1 and Influenza B.
“You have to accurately guess that the virus in the vaccine will match six months after you make the vaccine, and it’s notorious at how fast they mutate,” said Kendall.
Alberta Health’s deputy chief medical officer of health said one new product is a vaccine containing four strains—a “quadrivalent vaccine.”
READ MORE: A first for flu season: a new, more robust four-strain vaccine
“This is actually very helpful and useful for the children, because they’re more prone to infections with the different Influenza B strains, and so that’s why we’re targeting the use of this quadrivalent for children,” said Dr. Martin Lavoie.
Lavoie said compared to last year, there are two influenza As (one is new) and two influenza Bs (one is new).
“There is some kind of guessing, because the virus tends to change its genetic code fairly easily, so that’s the best guess we have at this point in time,” said Lavoie.
Dickinson said last year’s flu season was the first time health officials saw zero effectiveness for a vaccine.
READ MORE: Will this year’s flu shot work better than last year’s flop?
Flu clinic locations and schedules in Alberta are available online, and open Oct. 20. Click here for more.
With files from Heather Yourex-West
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