What to know about this year's flu virus

While the Ebola virus has been generating headlines, the disease is still relatively difficult to contract. Canadians should probbaly be more concerned about the flu virus as the annual season approaches.

Scientists are betting it will be similar to last year, at least in terms of the strains

The flu season can begin as early as October and end as late as May. (Pawel Dwulit/Canadian Press)

While the Ebola virus has been generating headlines, the disease is still relatively difficult to contract. Canadians should probably be more concerned about the flu virus as the annual season approaches. 

When is the flu season expected to hit? 

As the Atlanta-based Centers for Disease Control website notes, the timing of the flu season is very unpredictable and can vary from year to year, beginning as early as October and ending as late as May. In Canada, the bulk of cases generally occur between November and April, with most during a 10- to 16-week period beginning in December. 

How has Canada prepared for the flu?

The influenza vaccination components for this flu season have already been produced and are being distributed. Those components were determined by a scientific group in the World Health Organization, which met back in February. Last month, GSK, Canada’s largest flu vaccine supplier, said it was unable to complete its full vaccine order for the coming season and would be just under two million doses of flu vaccine short. 

The company, formerly known as GlaxoSmithKline, was under contract to provide nearly 6.4 million doses, which represents 53 per cent of Canada's total purchase of about 12 million doses.

The Public Health Agency of Canada, however, said it had found a replacement supply from other manufacturers that share the supply contract and promised that there will be no shortage of vaccine for the upcoming flu season.

What types of strains are they predicting this year?

No one knows with certainty what strains of the virus will circulate in any given season. The science is a kind of educated guess since the virus can change year to year, says Dr. Kevin Katz, medical director of Infection Prevention and Control at Toronto's North York General Hospital.

This year, scientists are predicting similar strains as the ones from last year, meaning that the vaccine components will also be the same as last  year.

The vaccine that's been produced for this flu season is to protect against:

  • an A/California/7/2009 (H1N1)pdm09-like virus;
  • an A/Texas/50/2012 (H3N2)-like virus;
  • a B/Massachusetts/2/2012-like virus.

How hard will the flu virus hit Canada this year?

Again, it's hard to say. "Influenza is a little bit unpredictable from year to year. Whether it will be a heavy year or not a heavy year, no one knows for certain until it actually evolves," Katz said. 

How effective were the vaccines last year?

Katz said that he believes there was a good vaccine match last year with the strain that circulated, and the fact that authorities didn't change the components this year is a good indication that the previous strains didn't shift in the middle of the season. 

Is FluMist better than other vaccinations?

​Approved for use in Canada in 2010, the FluMist nasal spray differs from other vaccines, which are called inactivated vaccines as there is no live virus in the vaccine at all.

FluMist is a weakened cold-adapted virus and for that reason, it's not recommended to be used by people who are immunocompromised or have severe asthma, or pregnant women.

The spray is covered under the public health plans of all provinces and territories except Ontario, Nova Scotia and New Brunswick.

Generally the flu vaccines are believed to be equal in effectiveness, Katz said.  However, there is some data that suggests FluMist may be more effective at boosting the response and preventing the flu in children aged two to 17.

With files from The Canadian Press