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

Australia is grappling with a severe flu outbreak, with over 20,000 cases and 60 potential deaths attributed to the highly mutated 'Super-K' strain of influenza A (H3N2). This aggressive variant, first identified in the US, is driving an unusually early and deadly flu season. Doctors warn of rising numbers, exacerbated by low vaccination rates, with updated shots now available. 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. More than 22,000 flu cases have been reported in Australia so far this year. Sixty-three deaths were recorded in January 2026, approximately double the typical figures for the month. Mater Director of Infectious Diseases Paul Griffin believes the Super-K strain has caused the unusually high number of deaths, noting it is easily transmitted and vaccination rates are at a six-year low.