Australia's 2026 influenza vaccine rollout and the Super-K strain
The new flu vaccination has been updated to include Super-K, experts say. (Getty image: Iparraguire Recio)
In short:
Experts are urging Australians to roll up their sleeves as soon as the 2026 influenza vaccine becomes available, following last year's low vaccine uptake and high caseload.
It comes as a fast-moving strain of influenza called subclade K, also known as "Super-K", is circulating in Australia.
What's next?
Influenza vaccines will be available in Australia from April, 2026.
Experts say they are feeling "nervous" as Australia approaches this year's flu season, with a new, fast-moving strain of influenza dubbed "Super-K" circulating as vaccine uptake dwindles.
Immunisation Coalition chairman Rod Pearce, who is a practising GP in South Australia, is urging Australians to roll up their sleeves as soon as they can to protect themselves.
He said last year's low vaccination rate and a high caseload of influenza led to the highest number of influenza-related deaths this century, describing it as a "perfect storm".
"We're anxious about the fact there is high-circulating flu in the summer, which means it's here, ready to take off early," he said.
"We're really nervous about low [vaccination] rates because people seem to be forgetting how nasty the flu is.
"Under-vaccination means less people are protected and more vulnerable people are vulnerable [to the disease]."
So what's new this year? And will Australia's 2026 influenza vaccine protect against a fast-moving strain known as Super-K?
What's new in 2026?
In Australia, vaccination for certain groups of people (such as older adults, pregnant women and babies) is funded under the National Immunisation Program (NIP).
Dr Pearce said this year older Australians would be able to get a higher dose of the vaccine, which would be more effective, and some Australian kids aged 2–17 would be able to have the vaccine administered through a nasal spray instead of an injection.
Will vaccines work against the 'Super-K' strain?
The vaccine against influenza changes every year, depending on which strains of the virus are circulating in Australia and the world.
"Influenza does something new and different just about every year," infectious diseases paediatrician Robert Booy explained.
Professor Booy, from the University of Sydney, said this year's jab was a trivalent vaccine, protecting against two influenza A strains and one influenza B strain.
Super-K is a subclade of the H3N2 strain of influenza A (seen above). (Supplied: NIH.gov)
A fast-moving strain of influenza A called subclade K, also known as "Super-K", has been circulating in Australia.
Dr Pearce said the Super-K strain appeared to be "easier to catch" but "not as severe" as others.
According to new study from Harvard Medical School, published today in the journal JAMA, flu vaccines administered in the United States during the northern hemisphere autumn last year had been less effective against the Super-K strain.
Researchers looked at the antibody responses in 46 healthy adults who received a trivalent influenza vaccine in Massachusetts, finding that although the US flu shots did offer some protection against the Super-K strain, there was a weaker antibody response.
Paul Griffin, director of infectious diseases at Mater Health Services in Brisbane, said Australia had already adjusted its 2026 influenza vaccine to ensure the population would be protected against Super-K.
"Our vaccine has been updated, our expert advisor group met towards the end of last year and recognised that Super-K was circulating and included a strain that should provide good protection against that this coming year," he said.
"The one that we're about to start using should hopefully offer much better protection against the flus that are likely … circulating, including subclade K."
Vaccines are created each year to target the main viruses circulating. (Getty Images: Science Photo Library)
Both Dr Pearce and Professor Griffin said it was not the vaccine efficacy itself which was their primary concern, but low vaccine uptake in the Australian population.
Influenza vaccination coverage data shows roughly one in three people had the flu jab in 2025, although the uptake was much higher in older age groups.
Dr Pearce said the 2025 flu season also started early and stretched out longer than a typical year.
When should I get vaccinated?
Influenza vaccines will be available in Australia from April, ahead of the peak of Australia's flu season, which is typically between June and September.
It takes about 14 days for the flu vaccine to become fully effective. People typically have the highest level of protection against the disease three to four months after they are vaccinated.
Professor Griffin urged Australians to get vaccinated as soon as they could.
"The main thing that people need to remember is that they just need to get one [vaccine]," he said.
"It's safe, it's effective, it's available soon."