Australia had its worst flu season on record. Is it a warning in Canada? – Nationally
As Canada enters the early stages of flu season, experts are warning that Australia's record flu outbreak could provide a worrying glimpse of what's to come.
The latest data from Australia's National Notifiable Disease Surveillance System shows the country has recorded 352,532 cases of laboratory-confirmed influenza this year, surpassing the previous peak of 313,615 cases in 2019.
Influenza vaccination rates in Australia have also fallen steadily, with national data showing consistent declines over the past two years.
“It is a cautionary tale. People forgot to get their vaccinations, the vaccination rate was very low and this led to an increase in the number of cases,” Dr Brian Conway, medical director of the Vancouver Infectious Disease Centre, told Global News Edmonton on Wednesday.
“The flu has killed people in all ages. A 15 percent decrease in the vaccination rate has led to an increase in cases and deaths,” he said.
Seasonal flu tends to cycle through the winter months, and Australia's flu season runs from May to October, while in Canada, it runs from October to May.
In Australia, the most prevalent flu strain this season was the A(H3N2) virus, a subtype of influenza A known to cause severe illness, particularly in older adults, young children and people with weakened immune systems.
In Canada, the country's weekly influenza surveillance data say it is too early in the season to determine which strain is dominant, but influenza A(H1N1) remains the most common strain. The data also show that the percentage of flu tests remains below the seasonal limit but is showing early signs of growth in Canada.
While southern hemisphere flu season trends can sometimes provide insight into Canada's flu season, they are not always reliable predictors, said Dr. Isaac Bogoch, an infectious disease specialist based in Toronto.
“Influenza is unpredictable. It is not yet clear what the flu season will look like as there are always curves,” said Bogoch. “Just because the Southern Hemisphere had a flu season doesn't mean we're going to have it again.”
Why was Australia's flu season so bad?
Australia's 2024 flu season has marked a significant increase, surpassing last year's total with more than 351,000 confirmed cases, up from 289,000 in 2023.
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This comes as a national survey by the Immunization Coalition found that fewer Australians choose to immunize themselves. Declining vaccination rates raise concerns about the country's preparedness for future flu seasons and highlight a growing public perception that the flu is not a serious disease, the coalition said.
“The record number of cases should be a wake-up call. The flu is not just a bad flu; can have serious consequences, especially for vulnerable people. However, our research shows that most Australians are comfortable and feel that vaccination is unnecessary. This puts the entire community at risk,” said Rodney Pearce, chairman of the Immunization Council, in a November 5 statement.
The flu vaccine helps protect individuals and communities by reducing the spread of disease, Conway said.
The goal is to achieve herd vaccination, he said, which requires at least 50 percent of the population to be vaccinated.
“This creates a high level of immunity in the community, reducing the spread of diseases as a whole. “However, in Australia, vaccination rates have fallen below this threshold, resulting in a high number of influenza cases,” he said.
Conway suggested one of the reasons Australians are hesitant to get their flu shot is vaccine fatigue that has emerged since the COVID-19 pandemic.
For example, a national survey revealed that 54 percent of Australian respondents did not see the flu as a serious illness, while 45 percent of parents did not know that vaccines were available for their children.
Although data shows that flu numbers in Australia have reached record levels, Bogoch noted that many questions remain unanswered. While poor vaccine availability can be a factor, other variables may be at play, such as whether health care professionals have performed more tests this season, leading to a higher number of reported cases.
Vaccine effectiveness can also have an impact, although data on this is often not available until several months into the flu season, Bogoch said.
What is in store for Canada?
Flu vaccines in Canada have already started being rolled out – and it's not too late to get yours – but it's too early to know the exact numbers.
However, national data for 2023 to 2024 shows that flu vaccination was 42 percent, which was the same as last season (43 percent).
While vaccination coverage for adults (73 per cent) is close to the 80 per cent coverage goal, only 44 per cent of adults aged 18 to 64 with chronic health conditions have received a flu shot in Canada, the data showed.
The most common reason for getting the flu shot was to prevent infection (23 percent), while the most common reason for not getting the flu shot was the belief that the vaccine was unnecessary (31 percent).
And despite most people agreeing that the flu shot is safe (87 percent), 43 percent of adults mistakenly believe they can get the flu from the flu vaccine.
Although vaccination numbers were lower than expected, Conway said it still helps reduce the risk of the flu in the community.
“We still had 100,000 cases, a few hundred deaths, and a few thousand hospitalizations, but we had it under control and it was a flu year. We can't really let that go up, so we need to go out there and get a gun and do all these other things to protect ourselves and others,” he stressed.
Canada is in the early stages of its flu season. Although the current case numbers are low, Bogoch said cases will increase as the season progresses.
“It's starting to take off, but it hasn't started yet. “I saw data that suggested it might have started slowly in Australia, but that didn't happen here,” said Bogoch.
“I think we're going to get it and of course, we're going to get COVID, and it's likely that they'll all go up at the same time as the flu and RSV, and we're probably going to have a rough time come January or February.”
