Unprecedented demand for the influenza vaccine has created a shortage of the potentially lifesaving injection across Australia.
With winter less than two weeks away, arrangements are underway to bring in additional supplies and those still seeking the vaccine, particularly the over 65s, have been advised to call ahead to ensure their GP has enough stock.
After a deadly flu season last year, a record 5.1 million doses of vaccine were brought into the country under the National Immunisation Program.
But a surge in demand of up to 30 per cent has impacted supplies, federal health authorities said on Monday.
"According to states and territories, compared to last year, there has been a 25-30 per cent increase in demand," Acting Chief Medical Officer Dr Tony Hobbs said in a statement.
To date, the Therapeutic Goods Administration has released 9.6 million doses of influenza vaccines under the immunisation program, state programs and the private market.
In 2017, the TGA released 8.3 million doses.
"The Department of Health is working closely with states and territories to monitor availability of vaccines," Dr Hobbs said.
The department is also working closely with company suppliers to ensure additional vaccines are brought into Australia.
In 2017, record numbers of Australians were diagnosed with influenza and more than 1100 flu-related deaths were recorded.
A fast-mutating and evolving strain of influenza A (H3N2) and an early start to the flu season defied efforts to stop the spread of the disease.
Influenza experts are expecting only a mild to moderate flu season in 2018.
Dr Vicky Sheppeard, Director Communicable Diseases at NSW Health said there was no indication there will be a repeat of last year's deadly winter.
She suggests the "tight" supply of the influenza vaccine was not cause for alarm.
"We expect the large majority of people who need the vaccine will have had it by now, based on previous years' orders," Dr Sheppeard said.
"Influenza activity remains low in NSW and there is no indication of an early start to the flu season," she added.
Dr Sheppeard said the most constrained stock under the NIP is the vaccine for the over 65s and NSW Health is working with the Commonwealth Government to source additional specific vaccine for this age group.
"We are advising anyone who is yet to have the vaccine to please call ahead to ensure their GP has the right vaccine for them in stock," said Dr Sheppeard.