Children, who appear at a relatively lower risk from Covid-19, are disproportionately harmed by precautions involved with lockdowns, warn researchers.

Experts from Oxford University Hospitals in the UK noted that while the role of transmission of SARS-CoV-2 by children is still uncertain, existing evidence points to educational settings playing a limited role when mitigation measures are in place.

Meanwhile, ongoing school closures and losses of other systems that help and protect children are revealing indirect but very real harm being borne by them.

For example, in the UK, it is estimated that the impact on education thus far may lead to a quarter of the national workforce having lower skills for a generation after the mid-2020s.

What's more, many countries are seeing more evidence of accidents at home requiring hospitalisation during lockdown periods and of adversely affected mental health in the young.

In the study, published in the journal Science, the authors address the concern that children in schools without symptoms may be "shedding" the virus, which could bring the virus home.

Understanding this is a key to resolving what has been an "unprecedented" global disruption to primary and secondary school education, they said.

They also cited studies that show minimal transmission from children positive for the virus to their contacts.

The coming months as schools reopen in the Northern Hemisphere will be an important opportunity to identify which measures schools are using to mitigate the virus spread are most effective, to generate a standard "best practice" that balances young people's rights to education with the need to protect the broader community from further transmission.

The authors said that advocates of child health need to ensure that children's rights to health and social care, mental health support and education are protected throughout future pandemic waves.

School closure should be undertaken "with trepidation" given the indirect harm it can cause, write the authors. Pandemic mitigation measures that impact children's wellbeing should only happen if evidence exists that those measures help, they noted.