A needle and syringe used to administer the flu shot in shown in Virgil, Ont., Oct. 5, 2020.Tara Walton/The Canadian Press
Hundreds of thousands fewer Canadians received flu shots this respiratory virus season than they did last season, and the drop could be contributing to the heavy toll influenza is taking on the health system.
Flu vaccination coverage rates are down between one and four percentage points in the eight provinces and one territory that provided data to The Globe and Mail.
British Columbia is typical of the trend: As of Feb. 9, 25 per cent of the province’s population was immunized against the flu, down from 28.2 per cent at the same time last year. The reduction reflects nearly 191,000 fewer shots in arms, the B.C. Ministry of Health said.
“That lower vaccine coverage rate translates into more emergency department visits and more pressure on our health care system in terms of hospital beds and even ICU beds,” said Jesse Papenburg, a pediatric infectious disease specialist at the Montreal Children’s Hospital, a facility slammed with flu cases in recent weeks. “The more we vaccinate, the more we’re also able to protect our health care system.”
Theories abound as to why fewer Canadians got the flu shot this fall and winter. Some experts say vaccine fatigue has taken hold since the pandemic, a hypothesis reinforced by the fact that coverage rates for COVID-19 vaccination are also down, according to provincial data The Globe collected. Others say it’s common for fewer people to seek out flu shots after a relatively mild influenza season. Still others say the main problem is access, particularly when an estimated 6.5 million Canadians don’t have a family doctor nudging them to get inoculated.
“My honest feeling is I think the numbers have been decreasing because a lot of the vaccine infrastructure that we created has been dismantled,” said Samir Sinha, a geriatrician and clinician-scientist at Sinai Health and the University Health Network in Toronto.
At the height of the pandemic, he helped organize a drive to vaccinate 10,000 homebound patients in Toronto against COVID-19 and other illnesses, including influenza. Extraordinary efforts such as those mostly ended when the pandemic emergency did, Dr. Sinha said.
Dr. Sinha is one of the authors of a recent Canadian study, based on an online survey, that found a significant disconnect between the share of respondents who believe the flu shot is safe (79 per cent) and understand why it is needed annually (86 per cent) and the share of people who reported actually getting a flu vaccine in the fall of 2023 (49 per cent).
That jibes with the results of the Public Health Agency of Canada’s 2023-24 survey on seasonal influenza vaccination coverage, which found the top reason cited for not getting the flu shot was “the perception that the vaccine was not needed.”
That perception is heightened when the last flu season is relatively mild, as the 2023-24 season was, especially in comparison with the 2022-23 “tripledemic” of flu, COVID and respiratory syncytial virus that preceded it.
“You have a quiet flu year and vaccination rates go down, a busy flu year and vaccination rates go up,” said Allison McGeer, an infectious disease consultant at Mount Sinai Hospital in Toronto who has studied influenza for decades.
The PHAC survey found that 42 per cent of respondents said they received the flu shot in the 2023-24 season, down slightly from 43 per cent the season before. The self-reported rate was much higher – 73 per cent – among seniors, who are considered high risk for severe flu illness.
However, none of the provinces that provided figures to The Globe reported flu coverage rates anywhere close to those in past PHAC surveys. The coverage rates, based on shots administered so far in the 2024-25 season, were 20.5 per cent in Alberta, 20.3 per cent in Saskatchewan, 22.8 per cent in Manitoba, 18.2 per cent in Quebec, 28.9 per cent in New Brunswick, 26 per cent in Nova Scotia, 22.7 per cent in Newfoundland and Labrador, and 17.8 per cent in the Northwest Territories. Flu coverage rates were down between 1.2 and 4.3 percentage points from last season in all those jurisdictions.
The Ontario Ministry of Health provided data on the number of influenza and COVID shots it distributed this season, but did not say how many had been injected or provide any figures for last season. Prince Edward Island, Yukon and Nunavut did not provide data before deadline.
Vaccine coverage rates are one of several factors that can affect the severity of the flu season. Two versions of flu A, H1N1 and H3N2, are circulating at the same time this season, which is unusual, Dr. McGeer said.
Canada is bracing for a later-than-usual peak of influenza A as rates continue to rise, with widespread activity in B.C., Ontario and Quebec. Nearly 27 per cent of all influenza tests came back positive in the second week of February, according to the Public Health Agency of Canada’s respiratory virus surveillance report – the highest since the start of the 2020-2021 season.
The effectiveness of the shot, which is revised annually to keep pace with the fast-changing flu virus, matters, too.
This year’s shot was found to reduce by 53 per cent the risk of getting sick enough with the flu to visit a health care provider, according to mid-season effectiveness estimates from a surveillance group led by the BC Centre for Disease Control. That effectiveness estimate is in the normal range, but lower than last year’s mid-season estimate of 63 per cent.