What to expect from Australia's 2026 flu season
By Dr Joe Milton, the Australian Science Media Centre
Australia’s flu season is off to a quieter start than last year’s record-breaking outbreak, but infectious disease experts say the virus is unpredictable, and vaccination remains the best defence heading into winter.
At an AusSMC Briefing this week, experts told journalists that influenza notifications in 2026 are currently running at about half the level seen at the same time last year, when more than 1,700 Australians died from flu-related illness - the highest death toll from flu this century.
More than 29,000 cases have already been reported nationally this year, according to the Australian Centre for Disease Control (CDC), although these official figures don't capture every single infection in the community.
“Influenza notifications in 2026 are currently still well below previous years,” said Dr Masha Somi, Acting Deputy Director-General of the Australian CDC. “But it is difficult to predict what we can expect each season.”
The experts said Australia’s 2025 flu season was unusually severe and prolonged, with the highest number of recorded notifications since national records began in 1991.
Professor Patrick Reading, Director of the WHO Collaborating Centre for Reference and Research on Influenza at the Doherty Institute in Melbourne, said a subtype known as H3N2 'subclade K' drove major outbreaks in both Australia and the Northern Hemisphere.
“We had a long and extended 2025 season — high numbers of deaths, the highest number of cases,” he said.
While flu activity in Australia is currently low, Professor Reading said cases are expected to rise as winter approaches. This year’s flu vaccine has also been updated to better match circulating strains.
“Influenza vaccines are the best way to reduce the likelihood of hospitalisation,” he said.
Despite this, vaccination coverage has been falling. Last year, only around six in 10 Australians aged over 65 received a flu shot, while uptake among children under five - who are eligible for free flu jabs - sat at around one in four.
Professor Kristine Macartney, Director of the National Centre for Immunisation Research and Surveillance at the University of Sydney, said healthy children are regularly hospitalised with flu, with records from 21 Australian hospitals recording more than 10,000 paediatric flu admissions since 2022.
“We know that the vaccine is typically around 50% effective in reducing hospitalisations,” she said.
“You can halve your chance of being hospitalised from influenza by having a vaccine.”
Prof Macartney added that we often underestimate the severity of flu, particularly younger and otherwise healthy people.
“I think one of the greatest misconceptions is that the flu is the sniffle,” she said.
“It’s not a cold.”
You can read more about the AusSMC Briefing here
This article originally appeared in Science Deadline, a weekly newsletter from the AusSMC. You are free to republish this story, in full, with appropriate credit.
Contact: Dr Joe Milton
Phone: +61 8 7120 8666
Email: info@smc.org.au