How COVID-19 vaccine could provide 'effective immunity'

Australia's Deputy Chief Medical Officer has provided some detail on how different COVID-19 vaccines would work - including the one Australia could be distributing next year in its new agreement with UK company AstraZeneca.

Dr Nick Coatsworth said the AstraZeneca vaccine, under development at Oxford University, was a "viral vector vaccine".

Australia's own researchers in Queensland have been focused on a "molecular clamp" style of vaccine.

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A molecular clamp involves using a polypeptide to maintain the shape of proteins in experimental vaccines.

It's designed to trigger a protective immune response to a virus.

"It is complicated science," Dr Coatsworth said.

"Science that's been generated and researched here in Australia with those vaccines in phase one studies at the moment."

Viral vector vaccines, by contrast, take a non-infectious virus and alter its genetic code to produce an immune response akin to that of COVID-19.

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"It stimulates less of the antibody-type response and more of the cellular-type immune response," Dr Coatsworth said.

"And that really does have the potential to take harness the dual aspects of the immune system, antibody and cellular, to give you enough of an immune response to make you effectively immune to COVID-19."

Dr Coatsworth suggested there might be an "incentive stick" used to increase vaccine take-up when it was available, but said it was too early to commit to any specific policy measures.

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He said regulations around international and interstate travel, and even moving in the community, would have to be discussed.

But he said he believed vaccine take-up would be high, pointing towards unprecedented rates of flu vaccination this year in the wake of the coronavirus.

Who gets the vaccine first?

A COVID-19 vaccine is still at least months away, but questions are already rising about who will be first in line for it.

Dr Coatsowrth said there would be a "prioritisation system".

"(The vaccine) may not be available to all Australians at once," he said.

Elderly Australians, people with co-morbidities and people with multiple health conditions were likely to be the priority recipients.

Health and aged care workers - those on the "front lines" against the pandemic - could also qualify.

"If and when it decided it will be clearly indicated to the Australian public," Dr Coatsworth said.

"But those decisions have not been made at this point and appropriately so, given we're not even at the manufacturing stage of the vaccine yet."