Australian doctors have advised residents, particularly the very young and the elderly, to already have their shots as they forecast a severe flu season for this winter.

More than any occasion, "now is the best time" to get vaccinated, John Dyson-Berry, a Mildura GP said, so as to reduce the risk of contracting or spreading the flu.

"When you get vaccinated, you're not just helping yourself and your family but everyone around you by stopping the spread of disease," Brian Owler, Australian Medical Association (AMA) NSW President, said in a statement on Monday.

Australian doctors and other medical professionals have forecast a severe flu season, following the trend of the northern hemisphere.

"The flu season mirrors the northern hemisphere's last winter and that was particularly bad," Dr Dyson-Berry said.

"The flu vaccination we get is about 97 per cent from the northern hemisphere flu season."

People aged over 65, indigenous Australians 15 and over, pregnant women and people with specific chronic diseases could get the flu vaccine for free, Mr Owler said.