Vaccinating 80 per cent of adults against coronavirus won’t be enough to end lockdowns, according to modelling urging Australia to immunise children as young as five.

While vaccinations are crucial, University of Melbourne epidemiologist Tony Blakely also flags they aren’t the only tool in the box.

Maintaining minimum density limits, people continuing to work from home, having mass rapid antigen tests and better air filtration systems would all help reduce lockdowns.

Professor Blakely foreshadowed vaccinating 90 per cent of the population down to the age of five would result in lockdowns being used 14 per cent of the time.

“What the modelling shows is that at 80 per cent of adults vaccinated, life won’t be tickety-boo next year. We need to do more than that,” he told the ABC on Tuesday.

“Sometime early next year, probably, we’ll get to 90 per cent. As people see their friends get incentivised because they see their friends getting sick, or as people realise that if they go to the pub or the community sports centre they need to be vaccinated.”

It comes as updated Doherty Institute modelling, underpinning a national reopening plan, predicted stay-at-home orders would be needed with double-dose rates of between 70 and 80 per cent.

Its initial advice compared outbreaks seeded with 30 cases. But the institute has now taken into account scenarios with hundreds and thousands of cases.

Its epidemiology director Jodie McVernon said conclusions about the 70 and 80 per cent vaccine goals remained robust under the updated model.

But “medium” public health safety measures should be retained during the transition between the targets in places like NSW and Victoria where new daily cases are in high numbers.

That includes staying at home except for essential purposes, retail and hospitality opening with density limits, working from home where possible and closed or graduated return to schools.

The modellers also cited falling case numbers in hotspot areas of Sydney as proof vaccination was working.

Mathematical biology professor James McCaw urged states without the virus to pursue high vaccination rates.

While border closures had been extremely effective, Professor McVernon said the Delta strain provided a reality check about the limited power of lockdowns and harsh restrictions in the future.

Australia has fully vaccinated 47 per cent of its population aged 16 and above, while 72 per cent have received a first dose.

Victoria had 607 more cases and another death on Tuesday.

On Monday, NSW had four deaths and 935 local cases, its lowest daily infection increase since late August.

There were seven new cases in the ACT on Monday, the first single-figure rise for almost a month.

-AAP