A third dose of COVID-19 vaccine, in addition to boosters, cannot be ruled out for the general population, according to Public Health, as discussion around a nation-wide booster program begins.
Meanwhile, the Federal Government has said a booster rollout for the aged care workforce may begin as early as November.
Currently a person is fully vaccinated when they receive two doses, while immunocompromised people are now receiving a recommended third dose for their cohort.
Public Health director Mark Veitch said a third dose, and then boosters, may be recommended for the general population in the future.
"A full course of vaccine is two doses of the currently used Australian vaccines. We may come to a point where there is a recommendation for a third dose as part of a primary course, as is the case for those with immunosuppression," Dr Veitch said.
He added that when a two dose, or three dose, primary course of vaccine had been administered, then a booster dose would be given.
"Down the line we might offer a booster dose, which is a single dose. Once you make it to the point where you've had two or three dose primary course, you could have it topped up with a booster course along the way."
In April this year, Pfizer chief executive Alfred Bourla said publicly that the need for a third dose six to 12 months after the last dose was likely, and then annual booster shots after that.
On Wednesday Federal Health Minister Greg Hunt said that a third booster dose for the general population of Australia is "likely" but would depend on advice from ATAGI and the TGA.
He said supply existed across Australia to give booster shots to the entire population.
Regarding aged care workers, he said the roll-out of a booster dose could occur in the second week of November.
"We want to commence that in the second week of November, subject to advice that we have and confirmation both from ATAGI and from the TGA," he said.
"We are ready, we're in a position to commence and to make sure that additional protection is provided."
He said the TGA had not yet received booster applications from all vaccine companies.
"Consideration through the TGA, which has to receive an application from the respective vaccine manufacturers, is in advanced consideration and we'll have a critical meeting next Monday with regards to the Pfizer vaccine. Moderna and AstraZeneca, at this stage, are still to submit their booster vaccine application," Mr Hunt said.
"But we are expecting that there will be two parts to any advice in relation to the TGA and ATAGI, and that would be aged care...and the general population."
Several countries have now started booster programs, with Australia seemingly keeping an eye on Israel's booster rollout.
"They've gone very rapidly with a ...booster program for the whole population, and we were able to look at the data ... And it very much confirms that this is a safe, that it is effective in all age groups for both decreasing infection as well as severe disease, and then for the older age groups .. prevention of death."