Under the National Immunisation Program, flu vaccinations are free for all frontline health workers, pregnant women, children under five years old and people over 65.

Vaccinations are also available for Aboriginal and Torres Strait Islanders, the homeless and those with chronic illnesses which predispose them to flu complications.

The vaccine has been available for the past two weeks in SA under the national scheme, with 233,000 doses distributed to immunisation providers.

There are about 13 million doses of the vaccine nationally, with eight million allocated for the program and the rest for the private sector.

SA Premier Steven Marshall said there were almost 30,000 flu notifications in the state last year, and he did not want that repeated.

"We don't need people unnecessarily in our intensive care units, taking up beds that we want to have ready for when the COVID-19 peak hits," Mr Marshall said.

"This is why we're making a plea to South Australians to get their free flu vaccinations early."

Mr Marshall said in previous years, people needed encouragement to be vaccinated, but that is not the case this year.

He said although there were no flu-related deaths so far and a slower start to the flu season compared to last year, South Australians should not be complacent.

"Many of the early onset flu conditions are brought from overseas and of course we haven't had as much overseas travel in the last month as what we'd normally have.

"That doesn't mean we can be complacent because we simply don't want ICU capability in SA taken up with flu cases when it should be preserved as much as possible."

Australian Associated Press