Manufacturing two different kinds of vaccines is "complicated technically", but biotech giant CSL is confident it has the capability to do so at the company's Melbourne facility.
The Australian government announced on Monday it had signed a Heads of Agreement deal with CSL and AstraZeneca, to manufacture 84.8 million COVID-19 vaccine doses for Australians.
Under the deal CSL would manufacture around 30 million doses of the Oxford University vaccine candidate, for which AstraZeneca is the main manufacturer, and 51 million doses of the University of Queensland candidate.
The deals and plans being made for the vaccines rely on the candidates to be proven safe and effective in clinical trials.
As part of the $1.7 billion committed by the government, $300 million will be spent on upgrading CSL's facility to be able to manufacture the University of Oxford vaccine, for which no capability currently exists in Australia.
In a briefing to journalists on Monday, CSL said the money would go towards modifications like new freezers, vial inspection machines and aseptic filling equipment.
CSL's vice-president of research and chief scientific officer Andrew Nash said the company was well-placed to manufacture the University of Queensland vaccine, but work needed to be done for the Oxford University vaccine.
"We need to do some structural re-configuring of airlocks and equipment to accommodate the manufacture of a live virus vaccine," Dr Nash said.
"We'll also need to bring in new personnel and retrain existing personnel as well."
Dr Nash said the company was already working with the the Therapeutic Goods Administration to ensure a successful vaccine candidate wouldn't face delays in being approved.
The number of doses ordered is based on an assumption that both vaccines will need two doses, an initial and booster injection, to be effective.
Production of the University of Queensland vaccine candidate is already underway at the Broadmeadows facility, to be used in late-stage clinical trials.
Prime Minister Scott Morrison described the deal as a "sovereign vaccine plan" on Monday.
Concerns have been raised Australia was lacking in capacity to manufacture vaccines and treatments for COVID-19, with most medical manufacturing happening offshore.
Even if the clinical trials for the vaccines were successful, manufacturing would take until September 2021.
"The best advice that we have - and it's not determined yet - is that there is likely to be multi-year protection," Health Minister Greg Hunt said on Monday.
"Nobody can say whether it will be lifetime."