Death rates from coronavirus are likely to increase in the coming days across New South Wales, infectious diseases expert Professor Robert Booy believes.
His grim prediction comes after NSW experienced its deadliest day of the pandemic so far with 15 people dying from 863 new infections.
Professor Booy says more people will lose their lives to the virus in the coming days due to the "lag time" in being infected.
"And that's because two to three weeks after you have an incident case, you can then have a death," Professor Booy told Today.
"It takes that long to get from mild, moderate, severe, hospitalised, dead. So, the lag time is such that even though the numbers are coming down on a daily basis, or starting to, the number of deaths will continue to rise for another few days, perhaps 10 to 14 days."
But the NSW Government is pushing ahead with its three-stage reopening plan, bringing forward the return of face to face learning by a week.
Kindergarten, year 1 and year 12 will now go back on October 18, a week after Greater Sydney's lockdown is due to end.
Year 2, 6 and 11 students will return on October 25, while the remaining grades will begin classroom learning on November 1.
All teachers must be vaccinated before going back to work.
Professor Booy said high vaccination rates among students will help to keep outbreaks at bay.
"We are going to get so much less transmission in schools over the next month because of better uptake, especially in teachers, but also in teenage boys and girls as well, of vaccination," he said.
And rapid-antigen testing may prevent whole schools from closing if a positive case was detected, he said.
"If you can isolate the cases to just one bubble, one classroom, that could be the maximum you shut down, and if you can catch them before they even come to school with rapid antigen testing, it might only be that child and the child next to them who don't come and the rest of them keep coming to school.
"The whole point of rapid antigen testing is keeping kids at school. If there is an outbreak, which will occur from time to time, there will be smaller and then larger shutdowns as needed."