OVERALL data from the few countries that have reopened schools has been "very reassuring" but governments need to consider what checks are needed to avoid a spread of Covid-19, a senior global health official has said.

Dr Soumya Swaminathan, chief scientist at the World Health Organisation (WHO), said decisions on whether to allow schools to open are often being done at a community or city level, based on factors such as whether the virus is under control.

She also told the BBC's Andrew Marr Show she believes that "society has to restart" but that there will be a new normal.

Asked about the reopening of schools, and evidence from countries that have done so, Dr Swaminathan said: "Overall, the data has been very reassuring, though of course it's only a few countries that have done that.

"The guidance that has been put out by WHO clearly lays out the criteria you would use when you consider whether to reopen a school or not."

Dr Swaminathan said this is based on factors such as the progress of the disease - whether it is on the rise or under control and going down, as well as whether there has been time to put measures into place such as rearranging classrooms and ensuring there are handwashing facilities.

"It's really important that all the stakeholders, that is the teachers, the children themselves and the parents or caregivers, have had a chance to have a dialogue and ask questions, and be informed of what is being done to minimise the risks and what they need to do," she said.

On Monday, the Prime Minister Boris Johnson announced plans to reopen primary schools for Reception, Year One and Year Six pupils on June 1. 

Dr Swaminathan also said evidence from countries where schools have remained open suggests this has not led to large outbreaks of Covid-19.

"What we have seen in countries where schools have remained open is that there have not been big outbreaks in schools, and where there have been it's been associated with events - where a lot of people gather, not in regular classrooms, and it's often been associated with an adult whose had the infection and has spread it," she said.