MORE than 100 of the COVID-19 cases in Victoria are children aged under 10, while in NSW more than 200 children under 10 tested positive just over the weekend.
Victorian COVID-19 response commander Jeroen Weimar said of the 494 active cases in that state, 112 were children aged under 10, 100 were between the ages of 10 and 19, and 79 are in their 20s.
"Again, it's a very, very young age profile," he said.
"We have seen kids get COVID and spread it to their families... transmit it to each other.
"No one is immune from this."
He said of the active cases in hospital, 21 of them were under 50 including an infant.
He said for those people in ICU one person was aged in their 20s and five were in their 40s.
In NSW, more than 2500 people under 20 have tested positive since the start of August.
NSW Health Minister Brad Hazzard told a Budget Estimates hearing on Monday that the Delta variant had shown a propensity to transmit amongst children "much more" than previous variants, on Monday.
He said there are "serious issues" around children in the current outbreak, which began in mid-June.
The national immunisation advisory group is considering whether to recommend vaccinations for children aged 12 to 15.
That age group is likely to be vaccinated in the near future, which would be an important control strategy, NSW Chief Health Officer Kerry Chant said.
And she is "very optimistic" that Australia will achieve high coverage rates when vaccinations do open up to children.
"I would anticipate that 12 to 15s will go quite quickly and the other younger children will have access to vaccine in the new year," Dr Chant said.
Victorian premier Daniel Andrews said there were 52,566 vaccination appointments available in Victoria over the next seven days.
"I'm hopeful that today and tomorrow people will be prompted to go and make an appointment," he said.
"Vaccination is our only way out of this, all the while driving the numbers down."
He encouraged people who had an appointment to not cancel or fail to show up because they may end up on a waiting list.
"Play your part in making sure lockdowns are not something we have to endure."
Asked if he was considering further restrictions Mr Andrews said there weren't too many more restrictions that could be put in place.
He said people were entitled to their opinions and had every reason to be frustrated.
But he said he didn't have enough supply of vaccine to get 70 per cent of the community vaccinated by next week.
"Compliance will drive numbers down," he said.
"If there was another option we would have chosen that... all politicians of all stripes would."
- with Australian Associated Press