Jay Weatherill, who now heads up childcare advocacy initiative Thrive by Five, told a Senate committee on Tuesday the lack of modelling resulted in an ad hoc response for younger Australians.

UNICEF Australia's child rights director Nicole Breeze said Australia needed to prioritise a national plan for children and young people as the country charts its path out of the pandemic.

"Children's priorities need more attention," she said.

"Much of the policy response to date has been developed primarily for adults.

"People's entire life trajectory are often set in place during childhood, adolescence and young adulthood and that is why it is essential we act now."

The plan also needed to focus on keeping schools open for as long as possible due to the added benefits they provide children, including building social skills and relationships.

The head of the Australian Research Alliance for Children and Youth Penny Dakin said schools needed to remain open for as long as possible, being the last to close and the first to open.

"Schools are more than just places of learning," she told the hearing.

The inquiry was also told COVID-19 vaccination coverage needs to be better spread across the country to protect young Australians who are not able to get jabbed.

More than four in five Australians over 16 are fully vaccinated but jurisdictions like Western Australia, the Northern Territory and Queensland are lagging behind the national average.

Australia does not have an approved vaccine for children under 12 and Health Minister Greg Hunt said it is unlikely one will be rolled out by January.

Strong vaccination rates were also driven by blitzes in Sydney and Melbourne during outbreaks, meaning regional areas have lower rates than major cities.

The lower levels of immunity regionally and in vulnerable groups like Indigenous communities leave children in those areas more exposed to the virus.

Australian Associated Press