Flu vaccine numbers are significantly lower than this time last year, with experts warning the flu season can be unpredictable.
Only 45 per cent of Australians aged between 18 and 64 have got the jab so far in 2021.
At the same point last year, 71.8 per cent of that age bracket had been vaccinated.
FluTracking shows that only 47.6 per cent of people who work with patients have been vaccinated, just over half of the number this time in 2020 - 88.6 per cent.
Professor Terry Nolan, public health physician at the Doherty Institute, says being protected from influenza is important because of the unpredictability of the flu season every year.
"It's never easy to predict what kind of flu season is ahead of us," he said in a statement.
While last year's season was mild, Professor Nolan says it is not uncommon to see flu "rebound".
"We should be alert and taking every precaution necessary to protect against the flu."
The Australian government recommends people wait at least 14 days between getting the season flu vaccine and their COVID-19 vaccine.
While there's no evidence that the two vaccines interact, the precautionary advice is to allow for proper safety and monitoring for both.
Jonathan Anderson, who is the head of medical affairs for vaccine manufacturer Sequirus, said Australia's peak flu season is usually between July and September.
That means it's not too late for those who want to book in the jab.
More than 800 flu-related deaths were reported in Australia in 2019.