The federal government has secured doses of another two COVID-19 vaccine candidates.
The prime minister will announce the government has advance supply agreements with Pfizer for 10 million doses of the mRNA candidate it is developing with German company BioNTech.
The vaccine is considered one of the leading candidates, in terms of time, with an efficacy readout from a late-stage trial expected in November.
The prime minister will also announce a deal for 40 million doses of the recombinant candidate being developed by Novavax.
The US-based company gained prominence in Australia in the early period of the pandemic after it initiated a phase one trial of its vaccine candidate at sites in Brisbane and Melbourne.
The two vaccines, which will both be imported in 2021, build on the government's previously announced deals with AstraZeneca and CSL.
Reports suggest the government has now invested more than US$3 billion for over 130 million doses of COVID-19 vaccine candidates.