Most flu deaths this century were recorded in 2025, ABS finds

There were more deaths associated with influenza last year than any other year this century, according to the Australia Bureau of Statistics.

The number of deaths in Australia involving influenza has also been higher than deaths related to COVID-19 since August 2025, the bureau’s latest report found.

The ABS released its latest data on deaths due to acute respiratory infections on Tuesday.

Last year, there were about 2,161 deaths involving COVID-19 and 1,701 deaths involving influenza.

There were also about 582 deaths associated with RSV, which was about a hundred more than in 2024.

Epidemiologist Catherine Bennett said the emergence of a new flu variant H3N2, known as Subclade K, has contributed to the higher rates of death.

“We had the highest rates that we’d seen for a long time continuing right through December and into January,” Professor Bennett said.

Flu replaces COVID-19 summer peak in 2025

The coronavirus has been the leading cause of deaths relating to acute respiratory infection between 2023 and 2025.

But there was sharp decline in COVID-19 deaths last year, with the number falling by more than half.

A total 2,161 people died of COVID-19, compared with 5,108 in 2024.

According to the ABS there has been a pattern of two peaks of mortality surrounding COVID-19 since the end of 2021.

One peak is between November and January, and the other comes between May and August.

Between January and July the number of COVID-19 deaths were about 1,279, higher than influenza deaths which were 682.

But during the second peak in summer between August and December 2025 there were about 741 influenza deaths, compared to about 428 COVID-related deaths.

There was a small fall in influenza deaths in November before they began to rise again in December.

Professor Bennett from Deakin University said the influenza strain Subclade K extended the flu season into summer.

She added that variant was different to other H3N2 variants.

“The H factor, the Hemagglutinin protein, had a number of different mutations in it that we hadn’t seen before,” she said.

“That meant the vaccine, or prior immunity, wasn’t as well targeted to this new virus.

“That’s why we saw more cases in this continuation of our winter outbreak.

COVID peaks decline

The ABS said it had begun to notice a shift in the severity of the COVID-19 peaks beginning in November 2024 and January 2025.

“When compared with October 2024 the number of deaths occurring during this period was much lower than other years,” the ABS said.

“Preliminary data does not show a summer peak in 2025-2026. The ABS will continue to monitor this as additional death registrations are received.”

Professor Bennett added that COVID-19 was becoming a seasonal virus which largely impacted the winter months.

“So winter, and if you look at the deaths it’s still a very significant virus, it’s still responsible for more deaths through the winter than influenza,” she said.

Summer flu peak not always likely, expert says

There have been other years where summer has seen a rise in influenza deaths, according to Professor Bennett.

In 2017 there were about 1,656 influenza deaths recorded.

“We did see a shift. It doesn’t mean influenza’s going to change and we’re going to have a summer wave every year,” she said.

“So it’s really a reminder that this year we’ve seen 2017 numbers for influenza deaths.

“That was one of our worst years on record.”

Professor Bennett said there were also a combination of factors at play contributing to the summer flu wave experienced this year.

“Vaccination rates are a lot lower and leaving more people vulnerable,” she said.

But the focus, she said, should be on increasing vaccination rates, especially for those over the age of 70 who are most vulnerable.

The majority of deaths related to COVID-19, RSV and influenza occurred in the over-70 age group.

That concerned Professor Bennett because only about 60 per cent of people over the age of 65 were covered by the flu vaccine.

“There’s still a lot of people who aren’t vaccinated, including in those groups where they’re vulnerable to severe disease that could in fact be a cause of death for them,” she said.

“So like all vaccines, it might not protect you from infection, but it can reduce the severity of disease and the likelihood that someone will pass away as a result of that disease.”