This is revealed in a new report, which also found unvaccinated adults, rather than children, were more likely to spread the disease.

The report also confirmed COVID-19 was generally mild in children, with only about two per cent requiring hospitalisation and many of those were admitted for monitoring and social care because their parents were ill.

Professor Kristine McCartney, a paediatrician and director of the National Centre for Immunisation Research and Surveillance, spoke about the report's findings on Wednesday.

It is the fifth report produced by the research group since the start of the pandemic.

Professor McCartney said there were almost 9000 educational facilities, including 3100 schools and 5800 childcare centres, in NSW.

"Of those 51 sites [which had COVID cases], the majority did not have any onward spread of the virus to teachers, staff or children," she said.

"The highest rate of spread was among unvaccinated adult staff and particularly in childcare centres.

"The spread of the virus also occurred between adults to children, but the spread between children themselves was very low."

Professor McCartney said the majority of children who became infected had not had symptoms or had only mild symptoms.

"We have seen high spread of the virus in households after there has been a case at an educational centre and we know that is primarily driven by unvaccinated adults," she said.

"We're very lucky to know, and it's consistent with data over the course of the pandemic, that COVID-19 remains generally mild in children.

"Only about two per cent will require hospitalisation and for many of those two per cent it is generally for monitoring and social care.

"Often, unfortunately, their parents are very unwell with COVID-19 and that's why they are being cared for in the hospital.

"We have seen extremely few children admitted to the intensive care unit."

Professor McCartney said the data was helping the government in preparations for a return to face to face learning.

"As a paediatrician and a parent, I know how important education is and having face to face learning is for development and mental health," she said.

"Families have really been suffering during this time and children have been having a hard time but there is light at the end of the tunnel and its really being delivered through those COVID safe practices."

The state government has announced a staged return of face-to-face learning, starting with Kindergarten and Year 1 from October 25.

Local government areas (LGAs) which remain listed as areas of concern will continue to have learning from home.