Health officials worried about an outbreak of influenza in British Columbia are encouraging citizens to get the flu shot, as this year’s strain is expected to be particularly aggressive.

Low levels of flu are already circulating in Vancouver area, and there have already been outbreaks at long-term care homes. One of the strains, H3N2, is known to be especially dangerous for vulnerable people. Physicians say it is the dominant flu strain this year.

Each year across Canada approximately 3,500 people die from influenza and its related complications, according to health officials.

The BC Centre for Disease Control says when the H3N2 flu strain is prominent in the community, there tend to be more hospitalizations and deaths than when other strains dominate. The elderly are most affected, but young children and people with compromised immune systems are also at risk.

The flu shot is critical protection for people such as Jacqueline Zweng, who is a currently a cancer patient.

Something like the flu that seemingly (causes) few small symptoms is actually life-threatening for somebody who’s vulnerable,” Zweng told CTV Vancouver.

She added: “For me, being immunocompromised, it’s essential to get the flu shot.”

Doctors are hoping more people see the flu shot as essential and get vaccinated.

“Influenza is a serious illness, it kills people in vast numbers, so please come on out and get immunized,” said Vancouver Coastal Medical Health Officer Dr. Meena Dawar. “Certainly early indicators are that this will be a heavy season.

Dawar said everyone is at risk from H3N2, but seniors and the elderly tend to get more severely ill.

Provincial Health Minister Terry Lake is also encouraging citizens to get vaccinated.

“The vaccine that we have this year is a good match to strain of flu that we’ve got,” Lake told reporters on Wednesday.

In British Columbia, the vaccine is free for anyone who is at higher risk for complications, and anyone who is in close contact with them. It takes approximately two weeks to be fully protected after getting the shot.

With files from CTV Vancouver