Canberra, Mar 27 (IANS): An expert on Sunday warned that Australia is set for a return of influenza in the wake of the Covid-19 pandemic.

Cases of influenza hit an all-time low in Australia in 2021 as a result of strict lockdowns and border closures that were implemented to prevent the spread of Covid-19, reports Xinhua news agency.

There were 598 confirmed cases in 2021 and zero deaths compared to 313,033 infections and 953 deaths prior to the pandemic in 2019.

However, Ian Barr, deputy director of the World Health Organization (WHO) Collaborating Centre for Reference and Research on Influenza, said that with restrictions lifted it was a matter of time until the flu returned to Australia.

"I think in 2022 we'll see the return of influenza," he told state broadcaster SBS.

"The only question is how severe the season will be, and that's difficult to judge. I don't think we're going to have a big year like 2017 or 2019, but we will see a low-to-moderate year I think."

Experts have warned that Australians' natural immunity to influenza has likely waned during the pandemic.

The national influenza immunization program will begin on April 4, with Australians urged to get vaccinated to protect the health system from a double blow of surging Covid and flu infections.

Barr said the vaccine was designed based on information collected by the Victorian Infectious Diseases Reference Laboratory on the influenza strains most likely to emerge in 2022.

"That involves isolating viruses, growing viruses, and then purifying and inactivating the viruses," he said.

"We make decisions around six-to-nine months before the viruses actually circulate, and make those available to manufacturers who scale up production and make vaccines."

On Sunday, Australia reported more than 40,000 new Covid-19 cases and 11 deaths, according to health department figures from states and territories.