The Moderna COVID-19 vaccine has passed the first stage of the Therapeutic Goods Administration's approval process, having been granted provisional determination.
It means Moderna can now seek provisional registration for the vaccine in Australia, which it is expected to do soon.
The TGA in a statement on Thursday said the US biotechnology company's mRNA shot would be considered for use in people aged 12 and older.
"While the vaccine has approval or emergency use authorisation in a number of other countries for older populations, it is currently under review in some of those countries for adolescent populations," the TGA said.
"If approved, a complete course of the Moderna vaccine is likely to be two doses given 28 days apart."
Australia has bought 25 million doses of the Modern shot, making it the second mRNA vaccine to be purchased by the federal government, after the Pfizer jab.
It was previously announced the Moderna order is expected to be delivered in two lots, with the first batch of 10 million doses to arrive in 2021 and the remaining doses to come in 2022.
However, the TGA says the vaccine will only be registered and supplied in Australia once it is approved as safe and effective.
Thursday's announcement follows news this week the AstraZeneca vaccine is likely to be phased out of the country's vaccine rollout later in the year, as the Modern shot and more Pfizer doses join the immunisation program.
The AstraZeneca vaccine is no longer recommended for people under 60 because of links to extremely rare but serious blood clots.
Under government vaccine distribution projections revealed on Wednesday, up to 2.3 million Pfizer doses could be allocated every week between October and December.
Moderna would join the rollout from September, with between 87,000 and 125,000 doses forecast to be distributed weekly.
