Calgary is experiencing one of its most severe flu seasons the city has ever seen, according to the head of emergency medicine for the Calgary zone.

The latest flu numbers show Calgary has had far more hospitalizations and deaths than any other part of the province before the Christmas season even hit.

The closeness of people around the holidays during travel and family gatherings meant an influx of patients at the city's emergency rooms that left hospitals in a "precarious" situation.

"It's been quite a harsh two, three weeks," Dr. Eddy Lang said Monday. "Things seem to be plateauing, but there is no immediate relief that we're seeing. The emergency departments are still very busy with the flu."

Patients waiting for beds

Lang said at one point over the past couple of weeks, 125 admitted patients — many with flu or flu-related complications — were stuck in Calgary's four adult emergency rooms waiting for beds.

"We had some emergency phone calls late last week as things were looking pretty serious in terms of the load of admitted patients in the emergency department and a number of procedures went into place," Lang said.

More staff were called in, closed wards were opened and patients waiting for long-term care beds were moved early to help accommodate the heavy patient load, which was straining the entire system. Lang said hospitals considered cancelling elective surgeries, but managed to hold off.

While new numbers from Alberta Health won't be available until Thursday, the latest numbers, released Dec. 21, showed of the 867 people in the province who had been admitted to hospital with lab-confirmed cases of influenza, 488 were in the Calgary zone.

The number of flu cases in Calgary, compared to the same time period last year, is 100 per cent higher this year, Lang said, with a more severe strain of the flu that is causing more prolonged period of illness. 

Vaccine mismatch

Craig Jenne, an assistant professor in the University of Calgary's department of microbiology, immunology and infectious diseases, said scientists are starting to see evidence that this year's flu vaccine isn't as effective as in past years.

"I think we're starting to see some evidence that the vaccination that was put together this year hasn't really matched the actual virus that well," Jenne said.

Influenza vaccines are designed to target more than one strain of the flu and while this year's vaccine missed in terms of the influenza A H3N2 strain, Jenne said the vaccine appears to be a good match for influenza B, which is also circulating and tends to target kids more often.

And science is starting to show there is good reason to not miss the annual flu shot.

"New evidence out this year says even when the vaccine completely mismatches, if you get vaccinated year after year, you might still get sick but you get less sick," Jenne said.

"Your immune system is still ready for that flu and there is still some overall protection if you get vaccinated every year."

With files from Jennifer Lee