Australia has signed a deal with the British pharmaceutical company AstraZeneca to supply a potential Covid-19 vaccine to its entire population free of charge should the trials succeed.

In partnership with Oxford University, AstraZeneca is developing the vaccine and has started advance trials. Under the deal, the Australian government would manufacture the vaccine and offer free doses to all citizens.

“The Oxford vaccine is one of the most advanced and promising in the world, and under this deal we have secured early access for every Australian,” said Prime Minister Scott Morrison in a statement released late Tuesday local time. “If this vaccine proves successful we will manufacture and supply vaccines straight away under our own steam and make it free for 25 million Australians.”

“However there is no guarantee that this, or any other, vaccine will be successful, which is why we are continuing our discussions with many parties around the world while backing our own researchers at the same time to find a vaccine,” he added.

Speaking on Wednesday, Morrison acknowledged that there were “big hurdles” in producing a successful vaccine but said the AstraZeneca-Oxford University project is “one of the best prospects in the world today.”

The deal is still in early stages, with both parties having signed a Letter of Intent. A final formal agreement at a later stage will lay out more concrete details like pricing and distribution. However, the Australian government has previously indicated that it will spend billions of dollars on its vaccine strategy.

AstraZeneca released early results of its closely watched Phase 1/2 trial in late July, which suggested that its vaccine candidate was safe and induces an immune response.

The Phase 2/3 trials will now aim to prove whether the vaccine protects people against the novel coronavirus. Results are expected later this year, and will depend on the rate of infection within the trial communities, AstraZeneca said.