FLU cases are already at significantly higher levels than last year and the Federal Government has not made this year's flu vaccine freely available to high-risk groups.
An Australian influenza expert says the Federal Government is a month behind its annual program on making this year's vaccine available to the elderly, pregnant women and anyone with a chronic condition.
Influenza Specialist Group chairman Alan Hampson said from January to March about 500 more Australians had caught the flu this year compared to last year.
But Dr Hampson said laboratory confirmed cases were just "the top of the iceberg" and these figures represented less than 5% of total flu cases.
The Federal Government-funded flu vaccine will be available as part of the National Immunisation Program from Monday.
The government said manufacturing delays were to blame for the lateness.
On Monday ISG released research that showed about 25% of people aged 35-64 years old had underlying medical conditions that placed them at risk of severe complications if they caught the flu.
But Dr Hampson said more than one in three Australians with one or more risk factors did not plan to receive the vaccination.
The data also showed 1500-3500 Australians died from the flu each year.
ISG director Robert Booy said the statistics were worrying.
He said the new research showed messages about risks associated with influenza were not getting through to the community.
"Flu clearly affects quality of life and may lead to serious health complications," Professor Booy said.
Meanwhile, Dr Hampson said the planned vaccine for Australians was a "good match" for the coming flu season.
Two of the three influenza virus strains in the vaccine will be different from last year's.
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