The Therapeutic Goods Administration has already approved the use of Remdesivir to treat COVID-19, but other trials for treatments have fallen over in trial stages.

"We're not just sitting back and waiting for our phones to ring," Health Department deputy secretary John Skerritt, who is responsible for the Therapeutic Goods Administration, told a parliamentary hearing on Thursday.

While not naming any companies or products, Professor Skerritt said the Therapeutics Goods Administration was in discussions with medical manufacturers who were in the process of trialling vaccine candidates and gave hope a vaccine could be expected soon.

"We're also having discussions with a number of companies that are large sophisticated multinational pharma, from whom we expect submissions in the coming months," he said.

When asked if that was AstraZeneca, the company with whom the Australian government is in talks over supply of the Oxford University vaccine candidate, Professor Skerritt said he couldn't say, "but you can read the newspaper".

"The other thing that's changed with COVID is we're having these discussions at a much earlier stage," he said.

"We've had discussions with one form of vaccine where we know we won't get a submission for 18 months. But the investigators wanted to know about clinical trials and regulatory requirements."

The use of already approved medications for off-label use to treat COVID-19 would be the decision of hospitals, which have their own drugs and therapeutics committees, Professor Skerritt said.

The TGA approved the drug Remdesivir within two weeks, the committee was told, much quicker than the 120-day turnaround that is required.

Australia is also part of a bloc of countries including Canada, Singapore and Switzerland working to approve drugs together, allowing for faster approval due to the countries pooling their resources.