However, influenza remains a major global pandemic threat, and experts say people must get vaccinated to protect the vulnerable from the deadly virus.

"The new influenza season this year in Australia is unlikely to be nearly as bad as the severe one we had last year. It was the biggest on record, although we did measure more flu as well as have more flu," said infectious disease expert Professor Robert Booy, Director of the Immunisation Coalition.

At the start of this week there had been a total of 11,057 laboratory confirmed notifications of influenza in Australia for 2018, according to data recorded by the Immunisation Coalition.

This is higher than previous years, although the numbers are on the decline.

Both influenza A and B strains were circulating at similar levels.

READ MORE:  Flu vaccine will be more effective this season

A fast-mutating and evolving strain of influenza A (H3N2) - the "worst kind" of flu - defied efforts to stop its spread in 2017 and was blamed for the majority of reported deaths, mostly among the elderly.

Professor Booy predicts this flu season to be "moderate to severe".

"We don't have any indication from the Northern Hemisphere that any new strain is going to cause substantial trouble," Professor Booy said.

In a bid to avoid a repeat of last year, health authorities have introduced a new, improved vaccine, plus free 'super vaccines' for the elderly.

The standard vaccine will again immunise against four strains of the flu, including an updated immunisation for the H3N2 strain.

However, no influenza vaccine is perfect because the virus mutates all the time, explained Laureate Professor Peter Doherty from the Department of Microbiology and Immunology at the University of Melbourne.

Vaccination, however, still provides the best protection against the nasty virus, which "continues to be our major known global pandemic threat", Professor Doherty said.

"The problem with influenza is it's a respiratory virus, and you can't decide not to breathe so you can't actually avoid being exposed to the influenza viruses," he warned.

Professor of Infectious Disease Epidemiology, Raina MacIntyre, says if people really care about the vulnerable, they will get the flu shot.

For a relatively healthy person, the beginning of May is the perfect time to get the flu shot, she said.

But if people have known risk factors like heart disease and diabetes, then they are advised to get it earlier.

"People who care for the vulnerable should get vaccinated, like child-care workers, aged-care workers. They all need to think about getting vaccinated to protect the vulnerable people they take care of," Professor MacIntyre said.

Australian Associated Press