What is Super-K flu? Doctors issue warning as 60 people die due to highly mutated strain ahead of flu season; all you need to know

Super-K flu strain has again grabbed the attention of scientists, doctors and health authorities with over 20,000 flu cases reported across Australia.

At least 60 people have potentially lost their lives from the deadly Super-K flu strain so far in 2026 triggering a warning from doctors who have claimed that there are high chances that numbers can rise, according to 9News.

What is ‘Super-K’ flu?

Subclade K, known as the ‘Super-K’ flu is the new and highly mutated strain of influenza A (H3N2). It was first detected in the United States leading to the deaths of dozens of children.

The H3N2 subclade was believed to be the driving force behind an unusually early flu season in Australia in January 2026, according to CSIRO.

22,000 flu cases reported in Australia in 2026

More than 22,000 flu cases have been reported in Australia so far this year, 9News reported, citing the Australian Bureau of Statistics. Sixty three deaths were recorded in January, 2026 approximately double the typical figures for the month.

Did Super-K strain cause high number of deaths?

Mater Director of Infectious Diseases Paul Griffin believes the Super-K strain has caused the unusually high number of deaths. "This is largely due to the Super-K variant, which is easily transmitted, and also due to low vaccination rates," he said, as quoted by 9News.

In 2025, around 25 per cent of children under five received a flu shot and 60.5 per cent of people over 65 were vaccinated. This was reportedly the lowest number in six years.

Flu vaccinations to begin in April

In Australia, flu vaccinations have been updated to tackle the new variant. This comes ahead of the flu season, which usually begins in April. But fewer people are reportedly getting their shots.

9News reports that only about one in three Australians are receiving their flu shots. Elderly, children, pregnant women and immunocompromised people are among those who are most at risk of flu hospitalisations and deaths.