Booster shots for COVID-19 vaccinations will continue to be delivered on a 6-month timeline following a review by health authorities prompted by uncertainty over the Omicron variant.
Chief Medical Officer professor Paul Kelly said the advice from the Australian Technical Advisory Group on Immunisations remained unchanged after a review into whether booster doses should be expedited.
The decision comes as health authorities continue to assess the severity of the Omicron variant and the effectiveness of vaccines against it.
"There is no evidence to suggest that an earlier booster dose of the current COVID-19 vaccines will augment the protection against the Omicron variant," Professor Kelly told reporters in Canberra.
"The advice from ATAGI remains a 6-month gap between that second dose and the booster program. So in summary, no change."
There have been nine cases of the Omicron variant identified in Australia, including eight cases in New South Wales.
Professor Kelly said he had held a meeting overnight with colleagues in South Africa - where the Omicron variant was first identified.
He said the COVID-19 variant had been identified as "transmissible", but to this point there was "no real evidence at the moment of an increase in severity."
"I would stress it is very early days. It is only in the last few weeks this has been circulating in South Africa and elsewhere, and there is that delay from cases to hospitalisations and deaths," he said.
"We remain, I remain cautiously optimistic, but we need further information."
There have now been 419 cases of Omicron identified in 30 countries around the world.
Professor Kelly said vaccine efficacy against the COVID-19 variant had also been shown to "still work" but their effectiveness continued to be assessed.
The World Health Organization has been critical of developed countries pushing booster shots for large parts of their fully vaccinated population when vulnerable people in poorer regions have not received vaccinations.
"There is no evidence that I'm aware of that will suggest that boosting the entire population is going to necessarily provide any greater protection for otherwise healthy individuals against hospitalisation or death," WHO emergencies director Mike Ryan said.
The federal government has stopped flights from eight southern African countries, where the variant was first detected, and brought in quarantine requirements from anyone who recently entered Australia from the region.
