Prime Minister Scott Morrison said his government had struck a manufacturing deal with CSL Ltd to produce an AstraZeneca and Oxford University Covid-19 vaccine, with 3.8 million doses to be delivered in January and February 2021.
Known as AZD1222, the AstraZeneca vaccine is undergoing late-stage clinical trials in Britain, Brazil and South Africa.
Australia in August said it would buy the AstraZeneca vaccine, but the deal appeared in some doubt in August after CSL said it was prioritising its own rival vaccine.
The hurdle was overcome when Australia on Monday said it had also agreed to buy CSL's alternative Covid-19 vaccine if trials are successful.
The agreement came as Victoria said 41 cases of Covid-19 had been detected in the past 24 hours, down on the 63 cases reported one day earlier and the lowest one-day rise since June 26.
Australia's second-most-populous state has been the centre of a second wave, now accounting for about 75% of the country's 26,320 cases and 90% of its 762 deaths.
The southeastern state on Sunday extended a hard lockdown in its capital Melbourne until September 28, as the daily infection rates had declined more slowly than hoped.
