Moderna hopes to roll out Omicron-specific boosters by next month, but experts warn older Australians not to wait

Omicron subvariants are believed to evade immunity at higher rates than their predecessors, prompting concerns Australians could delay their booster until a vaccine is tailored to the strain.

Moderna has revealed it hopes to make its updated vaccine, providing coverage against the original and Omicron strains, available as early as next month.

But Pfizer, also working to adapt its jab to the highly-infectious variant, warns it may be months away from submitting data to regulators.

And with availability not certain during the current winter wave, Australian National University infectious diseases expert Peter Collignon urged older Australians not to hold out for a dose they hoped would provide better protection.

"We need to accept that the biggest risk is if you're over the age of 70 and 80, and particularly if you're in aged care," he said.

"That's where we've got to concentrate on getting third or fourth doses, because that's where we'll get the maximum benefit."

Just 71 per cent of eligible Australians have received a third COVID-19 vaccine dose, but an additional 7.4 million Australians became eligible to receive a fourth last week.

Australians aged 50 and over were specifically recommended to receive an additional booster, which was also available to 30-to-49-year-olds.

Professor Collignon said, while he did not oppose younger people receiving a fourth dose, its effects would be notably lower compared to older cohorts.

"Providing they've had either two doses and a natural infection, or two doses and a booster, how much advantage they get from a fourth dose in that age group is fairly marginal," he said.

"It doesn't actually decrease your mild infection rate that much for very long, and probably doesn't make a lot of difference for your chance of dying and going into hospital.

"But that's quite different if you're unvaccinated."

Australia recorded another 31 deaths from COVID-19 on Monday, with more than 150 people in intensive care.

In April, the Therapeutic Goods Administration granted Moderna a provisional determination for an updated vaccine providing boosted coverage against Omicron.

On Monday, Moderna general manager Michael Azrak revealed its application had been finalised and was under evaluation by the TGA.

Mr Azrak said the updated vaccine showed "significantly higher neutralising antibody responses" against two Omicron subvariants - BA.4 and BA.5 - driving Australia's winter surge.

"If approved, the company will be able to supply this new Omicron-containing bivalent booster vaccine in early August, putting Australia amongst the first countries in the world to have access to this new COVID-19 vaccine," he said.

A Pfizer spokesperson said the company expected to submit data on its own Omicron-specific booster to the TGA in the "coming months".

Professor Collignon warned too many in the medical profession were sticking to a zero COVID target which had "well and truly sailed".

"We're now into living with COVID, and we're going to have to do that for five to 10 years. We need to actually better identify those most at risk," he said.

National cabinet maintains a "very strong" recommendation for mask-wearing in indoor settings, but has rejected calls to implement mandates.

Professor Collignon said officials would be "hard pressed to show [mask mandates] work", saying placing restrictions on younger people - particularly those protected by vaccines and prior infections - would prove "counterproductive".

ACT Chief Health Officer Kerryn Coleman on Monday tipped the territory's winter wave to peak in mid-August at the earliest.

Mirroring comments from federal Health Minister Mark Butler last week, Dr Coleman urged Canberrans to wear masks indoors but downplayed the effectiveness of mandates.

"I think people know what they need to do, and that they know that they don't need a mandate to wear a mask," she told ABC radio.

"We really need people just to wear those masks when they're indoors, and they're unable to keep that physical distance from people."

The Grattan Institute's Stephen Duckett, who led the Health Department under Paul Keating, believed Australia was "way past" the era of lockdowns, but said climbing cases meant "now is the time" for mandates to return.

"The cost to an individual of wearing a mask indoors is very low, and the benefits to the whole community is very high," he said.

Professor Duckett called for "crystal clear" messaging from the federal government.

And after Prime Minister Anthony Albanese was pictured without a mask as he received his fourth dose last week, Professor Duckett urged politicians to embody government advice.

"Leaders need to demonstrate it themselves," Professor Duckett said.

"They say they strongly recommend wearing a mask indoors, and they're indoors saying that without a mask. It's not the most sophisticated [approach]."

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