Australia's vaccination rate for children aged 12 to 15 has rapidly shot up just over a week after the cohort became eligible.
Almost one in five children in that age range have received a first dose in the eight days since they were included in the rollout.
"We're only a week down, pretty much, and we're seeing some really strong levels of vaccination," Prime Minister Scott Morrison told reporters in Washington DC.
Pfizer is being encouraged to apply to the Therapeutic Goods Administration for approval to use its vaccine on five to 11-year-olds after promising trial results.
"We've invited, of course, Pfizer to bring forward that information and to progress that through the TGA," Mr Morrison said.
He said that would enable the government to be ready to expand the rollout if the regulator approved the lower age limit.
Murdoch Children's Research Institute immunisation researcher Margie Danchin said vaccinating children was crucial despite coronavirus cases generally being less severe.
"Kids can still transmit the virus and particularly transmit it to adults," she told the ABC.
"Unvaccinated adults, unvaccinated grandparents are vulnerable."
Associate Professor Danchin said getting children back to schools and more normal lives was important.
She said the Pfizer trial results from 2200 five to 11-year-olds were promising but didn't show effectiveness.
"We know there's a robust anti-body response, but we don't know how well it will work to prevent clinical disease in kids."
Australia has fully vaccinated 48.5 per cent of people aged 16 and above while 73.4 per cent have had a single dose.
NSW reported 1035 new cases and five deaths on Wednesday, with the outbreak's toll rising to 260.
Victoria, which has been rocked by violent anti-vaccination and anti-lockdown protests, detected 628 new local cases and three additional deaths.
The prime minister condemned the demonstrations as unacceptable behaviour.
"The protest activity and what we've seen there, I think, is highly distressing. That is not an appropriate response to trying to deal with an outbreak of this nature," Mr Morrison said.
"None of us are above the law."
Coalition for Epidemic Preparedness Innovations chair Jane Halton said most people around the nation were doing the right thing "unlike those 2000 people who went berserk in Melbourne".
The former health department boss fears the rallies could lead to a spike in coronavirus cases.
"It is a real risk," she told the Nine Network.
"You see how close all these people are together, how long they were together, how long they were together yesterday."
Australian Associated Press