The head of Australia's vaccine rollout John Frewen said the country's vaccine advisory group will soon release its advice on boosters.
"We're just waiting on the finalised medical advice now," Lieutenant General Frewen told the Nine Network on Monday.
"We expect it will recommend probably between six to 12 months when people should consider having a booster shot."
Immunocompromised Australians are already eligible to receive a booster shot.
Nationally, 73 per cent of eligible people aged 16 years and over are fully vaccinated, while nearly 87 per cent have received their first dose.
The Therapeutic Goods Administration is reviewing booster shot data from overseas before making its final decision.
"This timing, or sweet spot, of around six or a few more months (between doses) is looking good," National Centre for Immunisation Research and Surveillance director Professor Kristine Macartney said.
"It's what the majority of countries have gone with now," she told ABC radio.
"This is a brand new virus in the world, we essentially need to train and then train a bit more our immune systems to respond to it."
Lieutenant General Frewen said mRNA vaccines, such as Pfizer and Moderna, would be predominantly used for booster shots.
Australians in aged care, disability care and front line health workers are expected to be among the first to receive top-up jabs, once approval is granted.
Meanwhile, Victoria recorded a drop in its daily virus cases, with 1461 new infections and seven deaths reported on Monday.
The number of Victorians in hospital with COVID now stands at 802, with 152 in intensive care and 92 on ventilators.
NSW recorded another day below 300 cases, with 294 reported on Monday.
There were four more deaths, taking the toll from the state's outbreak past 500.
NSW has fully vaccinated almost 85 per cent of people aged 16 and above.
The state's COVID-19 restrictions eased further on Monday, with all school students able to return to classrooms.