Australia’s path out of lockdowns is looking increasingly unclear after one of the epidemiologists responsible for the modelling underpinning the nation’s exit plan said it was being revised.

As New South Wales reported 830 new locally acquired cases of COVID-19 and Victoria another 65 on Sunday, Doherty Institute director of epidemiology Jodie McVernon told Sky News on Sunday that the institute had not envisaged “shifting from phase A to phase B from a situation of lockdown”.

“I think it’s important to differentiate between what our [national cabinet] report is discussing, which is making a transition from a state of no or very few cases to a more immunised environment, and then thinking about how transmission might be managed there, as opposed to coming off a high caseload,” Professor McVernon said.

“Obviously we were not envisaging shifting from phase A to phase B from a situation of lockdown, which is where we are now.”

Phases A and B refer to the first two steps of the federal government’s four-stage exit plan.

The plan was underpinned by advice from the Doherty Institute that said “stringent lockdowns” would become “unlikely” once 70 per cent of the adult population had been vaccinated.

But Doherty’s modelling was based on the assumption that daily case numbers would be no higher than 30 when moving into phase B of the plan.

‘Really important work’

Given daily case numbers today are much higher than that, Professor McVernon said NSW Health had commissioned the Doherty Institute to conduct separate modelling on the restrictions the state could realistically ease with high case numbers when it reached a vaccination rate of 70 per cent.

She said it was “really important work” led by Dr James Wood at the University of New South Wales.

“It can help decision makers think through in these uncertain times what might happen next,” Professor McVernon said of the new modelling.

Her comments cast a shadow over the nation’s four-stage exit plan and appeared to contradict responses given by Prime Minister Scott Morrison in an interview on ABC’s Insiders program.

“The advice that we have from the Doherty Institute is that the starting point does not ultimately alter the conclusions of the modelling,” Mr Morrisons told show host David Speers.

“And so, of course, we continue to always update these things, so we’re best informed about how to manage the public health response.

“And, of course, we’ll do that. But the 70 per cent marks, and the 80 per cent marks, the way that we can move forward.”

Mr Morrison said Australia has to learn to live with the virus and “lockdowns do more harm than good” once more than 70 per cent of the adult population is vaccinated.

The Nine Newspapers reported on Sunday that the Doherty Institute has provided the government with further advice to be presented to national cabinet this week, which says that “reopening with hundreds of daily cases at 70 per cent vaccination would not dramatically change its epidemiological modelling”.

But not all state premiers see the situation in the same way as Mr Morrison.

NSW Health Minister Brad Hazzard refused to say if the state would adopt a targeted approach to the easing of restrictions. Photo: AAP

Patchwork quilt of restrictions

Western Australia Premier Mark McGowan has said he would continue to pursue ‘Covid zero’ even after the state achieves 80 per cent vaccination.

Queensland Premier Annastacia Palaszczuk said last week it was too early to say how the state would manage the pandemic once the 80 per cent target was reached.

And, on Sunday, NSW Health Minister Brad Hazzard also refused to clarify how the state would oversee the lifting of restrictions.

Asked whether the state government would end the lockdown in Sydney once the city had achieved 80 per cent vaccination if other parts of the state had not, Mr Hazzard said: “Let’s work through that … I think you’re jumping ahead.”

It was further evidence that Australia’s path out of the pandemic remains shrouded in uncertainty even after the release of the four-stage exit plan.

But Mr Morrison was clear in his Insiders interview that he wanted state premiers to open up once crucial targets were hit.

“You can’t live with lockdowns forever. And at some point, you need to make that gear change,” he said.

“And that is done at 70 per cent, because that’s where we’re advised from the medical science that you can make that gear change.”

The New Daily contacted the Doherty Institute for comment.