A Senate estimates committee heard on Thursday the Australian Health Protection Principal Committee had been asked for advice relating to the early childhood education sector.

The advice, and research by the Doherty Institute, will go to the next national cabinet meeting of federal, state and territory leaders on November 5.

"The health minister has asked for advice ... on additional ways to reduce transmission in childcare," Government Services Minister Linda Reynolds said.

Advice relating to schools showed the Delta variant did not cause more severe disease in children than past variants, she said.

The upper house committee also heard the federal education department did not know how many early childhood workers were vaccinated across the country, as it was a matter for the states and territories.

But the department has asked governments for those figures.

Five states and territories have so far mandated vaccinations in the early childhood sector and the vaccination of workers was strongly encouraged, department deputy secretary Brenton Philp said.

Senator Reynolds said premiers had been encouraged through national cabinet to ensure the vaccination of "critical workers", including in the aged, disability and childcare sectors.

Health regulators are yet to make a decision on the vaccination of children under 12.

Australian Associated Press