If you received your flu shot this year but still caught a cold, you're not alone.
Researchers have found that this year's seasonal flu shot only had an effectiveness of 10-20% in Canadians.
Medical Health Officer Dr. Mark Vooght explains why the vaccine is less effective than in previous years.
"It's like a game of poker where the virus holds a very good hand. The virus is quite clever and can change its hand by changing the structure of the virus continually. This is what's happened."
"The problem is that there is no quick update; there just isn't a quick fix. The structure of the vaccine is set [at least nine months] in advance. All the production lines are set up and they just can't change it week to week; it's just not possible."
The same vaccine was used in Australia for their flu season last year and was found to be just as ineffective. The World Health Organization will meet in February to come up with a plan for next year's flu vaccine.
"It's still very important that people take the basic precautions. Frequent hand washing, soap and water, and stay at home when you're sick. Don't go to school, don't go to work [or] you're just spreading it to your friends and others."