GENEVA, June 12 (Xinhua) -- The World Health Organization (WHO) said on Friday that it's difficult to make "universal recommendations" on children returning to schools, and that WHO is working on offering guidance so that "context specific" decisions can be made.

"At school level, it is very difficult to give a universal recommendation around school opening or closing, as you can imagine the contexts are extremely different," Michael Ryan, Executive Director of WHO Health Emergencies Program, said at a press conference from Geneva.

"The epidemics are very different, the vulnerability of children in different settings is very different, a school is a very different concept in many parts of the world, the age stratification, and what you do in young children versus older children versus adolescents versus universities, so it's very difficult to make universal recommendations," he explained.

Anshu Banejee, Director of Department of Maternal, New born, Child and Adolescent Health and Ageing, said considering both the negative impacts of school closures and its impact on transmission, it's important to "identify better what the impact has been of closure of schools on transmission in the community."

"We have also identified that closure of schools has contributed or will contribute to poorer educational outcomes, to mental health issues... but also to poorer nutrition -- many children actually depend on a meal at school as part of their need for their nutritional status, as well as looking at the impact of violence against children," he said.

"So I think we need to really look at the balance: what is the risk or what is the impact of closing schools, the impact on children versus the transmission in community, and that's something that we're studying at the moment," he said.

Maria Van Kerkhove, Technical lead COVID-19, WHO Health Emergencies Programme, said: "It's very context-specific and so to set one policy is very difficult... what we're trying to do is to help the decision maker to take those decisions to reopen schools safely."