"When implementing the national plan we must be realistic, careful and test each change and the impact of measures before moving to the next phase, given that there are thousands of COVID-19 cases in the community," he said.
Dr Khorshid said the Doherty modelling does not show the impact on hospitals, which are already under extraordinary pressure.
"The health system needs to be much better prepared to deal with the growing burden of COVID-19, as well as be able to deliver non-COVID-19 related care," he said.
The Doherty Institute, who's modelling the nation's recovery plan is based on, was asked to undertake additional "sensitivity analyses" of the scenarios presented in its initial report.
It was asked to test the robustness of the recommendation to transition to Phases B and C of the national plan at 70 and 80 per cent vaccination coverage if COVID-19 infection was already established in the community.
"These findings confirm our earlier strategic advice that even high levels of vaccination will not be sufficient to stop COVID-19 in its tracks," the institute said in a statement.
The institute's Professor Jodie McVernon and University of Melbourne's Professor James McCaw will hold a press conference to further discuss its findings on Monday.
Victorian Premier Dan Andrews released his long -awaited road map out of lockdown as the state recorded 507 new cases and another death, bringing its toll from the latest outbreak to 11.
The road map includes scrapping the nightly curfew once 70 per cent of Victorians are fully vaccinated.
But substantial changes will not be made until 80 per cent of people are immunised, which is forecast to occur around November 5.
"We are opening up, no doubt about that, and there will be no turning back," Mr Andrews told reporters in Melbourne.
"If you care about nurses, doctors, ambos, cooks and cleaners, everyone in our health system, if they're important to you, then get vaccinated."
NSW reported 1083 new virus cases on Sunday and 13 deaths, bringing its toll to 231 since its Delta variant outbreak began on June 16.
Premier Gladys Berejiklian announced recreation rules will be relaxed for 12 LGAs from Monday and they'll enjoy extra freedoms, a week after they were granted to the rest of the state.
These include fully vaccinated adults being able to exercise outdoors with no time limits and gather in groups of five for outdoor recreation within five kilometres from home.
But the premier warned the state is still in a "precarious" situation and case numbers will increase when it reopens at the 70 per cent double vaccination target.
"We are anticipating our worst weeks in ICU and hospitals will be in October," she said.
The ACT, the third jurisdiction currently under lockdown, reported 17 new virus cases.