B.C. may be in for one of the deadliest flu seasons in recent years and public health officials are hoping more at-risk residents get vaccinated.
But they're facing an uphill battle – use of the influenza vaccine dipped to around 35 per cent of the B.C. population last flu season, after peaking a year earlier at nearly 40 per cent.
Dr. Danuta Skowronski, an epidemiologist with the B.C. Centre for Disease Control, said she believes some people skipped the vaccine last year following disclosure that the 2014-15 vaccine gave virtually no protection against the flu strain that ended up circulating.
That mismatch problem doesn't appear to have resurfaced this year, however.
Skowronski said signs so far indicate the more dangerous H3N2 influenza strain will dominate this flu season and "pack quite a wallop" following a relatively mild H1N1-dominant flu season last winter.
"H3N2 viruses are associated with the greatest disease burden – more intense, severe epidemics, more hospitalizations and deaths," Skowronski said. "A number of us are concerned that it's H3N2 we're likely facing this year. We are already picking up care facility outbreaks due to H3N2 viruses. That is very early."
The new vaccine formulation includes an H3N2 component that so far appears to be a good match to the strain in circulation so far.
"That can change. That can flip flop. But at least going into the season, that's looking promising."
She added that how well the vaccine fits the virus is only one of the factors that drives the effectiveness of flu vaccines.
The H3N2 vaccine effectiveness has traditionally hovered around 50 per cent, she added, so even if it's well matched against what's circulated, protection is not assured.
"It doesn't mean that you are invincible if you get the vaccine, but I'm certainly expecting more decent protection than had I been picking up signals in the circulating virus that it was drifting away from the vaccine component."
Skowronski said she hopes high-risk people in particular – the elderly and those with chronic medical conditions – aren't dissuaded from taking the vaccine this time.
"The vaccine can be a life saver and it would really be a tragedy if they chose not to get the vaccine because one year happened to be a miss on the match."
National statistics show the worst flu season of the last five years – 2014-15 – resulted in nearly 600 deaths across Canada and more than 7,700 hospitalizations from confirmed cases.
But Skowronski cautioned that any statistics of that sort grossly undercount actual deaths because most victims are never tested to confirm a flu virus.