Recorded flu numbers drop drastically but expert warns caution

More than 33,000 flu cases have been detected so far this year, down from 96,422 in 2025 over the same period. (Supplied: NIH.gov)

There's been a big drop in recorded flu cases this year following the deadliest year for influenza this century in 2025.

The Australian Centre for Disease Control believes there might be increased population immunity because so many people were infected last year.

One expert has warned against complacency and urged more people to get vaccinated especially amid a global resurgence in preventable diseases like hantavirus and Ebola.

The number of influenza infections recorded in Australia so far this flu season is below average, but one expert has cautioned against complacency.

According to the latest respiratory surveillance report, released today by the Australian Centre for Disease Control (ACDC), there's been a 65 per cent drop in notified flu cases compared to the same period the last year.

There were 33,071 cases detected between January 1 to May 31 this year, down from 96,422 cases over the same period in 2025.

But Mater infectious diseases physician Paul Griffin said each year was different and the community should not be "lulled into a false sense of security".

"Part of that is because we had an extraordinary flu year last year with record-breaking numbers and lots of activity also outside of the usual season," Professor Griffin said.

Paul Griffiin says the numbers should not lull people into a false sense of security. (ABC News: Chris Gillette)

Last year 1,701 deaths were associated with influenza — the highest number this century.

The ACDC report noted the drop in cases could reflect the fact people who caught the flu last year would have built up immunity against the infection.

"Reduced overseas importations of influenza, due to earlier activity in parts of the northern hemisphere during their 2025–26 season, may also be contributing," the report said.

Mr Griffin said the fast-moving Super-K strain of influenza was still causing "the majority" of infections.

In the last two weeks of May there were 1,903 new flu cases reported by health authorities, a 15 per cent increase from the previous fortnight.

Flu cases typically increase over winter, peaking around August.

Catherine Bennett says flu cases will likely peak later than usual in 2026. (Supplied)

Deakin University Epidemiology Chair Catherine Bennett said the increased population immunity would likely delay the peak case load to later in the year.

"If people top up that late boosting they had at the end of last year with a vaccination now, we coul