Reopening Australia before four in every five Australians are vaccinated risks the rampant spread of coronavirus and hospitals being overwhelmed, the Grattan Institute says.
The think tank released modelling on Thursday suggesting allowing COVID-19 to spread with half the population vaccinated would lead to 31,440 deaths within 300 days.
The need for intensive care beds would also peak at 60,000.
"Abandoning our Zero COVID strategy before 80 per cent of Australians are vaccinated would risk a rapid surge in COVID cases that overwhelms our hospitals and imposes a high death toll," the Race to 80 report says.
The situation remained dire even with 75 per cent of the population vaccinated.
A Delta variant with a reproduction number of 6 (R6) would likely cause 320 deaths if all restrictions were dropped. The nation's hospitals would also be treating up to 160 ICU patients a day.
Those numbers rose to 7590 deaths and 8110 ICU admissions under a more virulent strain (R7).
About 14 per cent of Australia is fully vaccinated, with another 17 per cent partly vaccinated. About 17 million people are unvaccinated.
More than 200,000 shots were given on Wednesday, a new record.
The report says a vaccination rate of 80 per cent - plus 95 per cent coverage in over-70s and high-risk individuals - equals few deaths and severe illnesses.
That rate could be achieved by year-end, if a vaccine becomes available in coming months for children aged under 12.
Delays on that front could hinder any reopening until March, as the country waits for more adults to get the jab.
Currently, the Therapeutic Goods Administration has only approved the Pfizer vaccine for use in children aged 12 to 18. The AstraZeneca jab is approved for all adults.
The Grattan report's authors recommend national cabinet commit to the "80 per cent by December 31" target.
They also called on governments to immediately accelerate the vaccine rollout by turning workplaces, schools and community centres into makeshift vaccine hubs ahead of large Pfizer shipments in October.
Once supply issues were overcome, government should introduce a weekly $10 million VaxLotto, starting on Melbourne Cup Day (November 2), giving every vaccinated Australian and those with medical exemptions an entry.
"Australians shouldn't and won't accept high death tolls or indefinite restrictions," report co-author Brendan Coates said.
"Racing to 80 per cent and then pushing on to 85 per cent is Australia's ticket to opening up. Failure is not an option."
Australian Associated Press