With winter closing in, health experts are urging people to get vaccinated against respiratory diseases, warning that the flu can be deadly.
There have been more influenza B cases so far in 2025 than at the same time in recent years, particularly in school-aged children and young adults.
Chief Medical Officer Anthony Lawler said people should vaccinate themselves against influenza and other respiratory diseases.
These include respiratory syncytial virus (RSV), whooping cough if you are pregnant, and COVID-19 if you are in an at-risk group.
"Influenza, RSV and COVID-19 are not the common cold," he said on Monday.
"These are very serious viruses that can cause severe illness, hospitalisation and even death among otherwise healthy children and adults."
In 2024, the highest number of influenza cases reported to the Australian Health Department were in children younger than nine years, a group with a low vaccine uptake rate.
The number of RSV cases was higher in 2024 than 2023, and most were in children up to four years of age.
The highest number of reported COVID-19 cases were in people aged 70 and older.
There were also more deaths in 2024 involving influenza and RSV than in 2023.
Public Health Association of Australia chief executive Terry Slevin said vaccinations prevented people from getting ill and saved lives.
"If you don't want to get crook get vaccinated," he told AAP.
"You're less likely to get crook and if you do get crook, you'll be crook for a shorter period of time ... and reduce the misery."
Adjunct Professor Slevin said many people lumped colds and the flu together as relatively minor ailments, but influenza could cause up to 2000 deaths per year.
Most of those are in people aged 80 or older but young people and children are also vulnerable.
"RSV is a particularly nasty disease for little kids and so it's not something to be taken lightly," he said.
People aged six months or older should get vaccinated against influenza every year.
Pregnant women should be vaccinated against RSV and whooping cough and people 65 years and older should have regular COVID-19 vaccinations.
Influenza, RSV and COVID-19 vaccines are available at GP clinics, pharmacies, community health centres, Aboriginal Medical Services and immunisation clinics.
It is safe to get all the influenza, RSV, whooping cough and COVID-19 vaccines at the same time.
People eligible for a free influenza vaccine include children aged six months to less than five years and pregnant women at any stage of pregnancy.
First Nations people aged six months and older, people aged 65 years or older, and people aged six months and older with certain medical conditions are also eligible.
People not eligible for a free vaccine can purchase it, with many workplaces offering free annual influenza vaccines.
