Coronavirus: School closures have limited impact on spread of outbreak, study suggests

School closures do not appear to have a significant effect on the spread of infections during outbreaks such as Covid-19, a study suggests.

Researchers found that school closures alone were predicted to reduce deaths by around 2 per cent to 4 per cent amid the Covid-19 outbreak in the UK, which is less than other social distancing measures.

Closures have only small effects on infections with a high reproductive number where children are not the main drivers of infection, such as Covid-19, according to the research led by University College London (UCL).

Schools across the UK closed their doors to the majority of students more than a fortnight ago.

The move came after countries around the world implemented mass school closures amid the Covid-19 pandemic.

Researchers analysed 16 studies – which included articles on severe acute respiratory syndrome (Sars), as well as a report on Covid-19 in the UK.

The study in the Lancet Child & Adolescent Health journal suggests that school closures did not contribute to the control of the Sars epidemic in China, Hong Kong and Singapore in 2003.

It also finds that school closure, as an isolated measure, has a limited impact during a Covid-19 outbreak, whereas other control measures, such as case isolation, are more effective.

The paper says: “Modelling studies from the Covid-19 pandemic support the use of national school closure as part of a package of social distancing measures.

“Yet the only study to examine school closures as a separate intervention warned that the impact was relatively marginal, given the reasonable assumptions that household and community contacts would rise as a consequence.”

Researchers added that the “economic costs and potential harms” of mass school closures are very high – especially for the most disadvantaged children.

They concluded that policymakers should consider introducing other social distancing interventions in schools – such as closing playgrounds and increasing spacing between students in class – which are less disruptive than full closures in a bid to control the virus.

Russell Viner, professor of adolescent health at the UCL Institute of Child Health, said: “We know from previous studies that school closures are likely to have the greatest effect if the virus has low transmissibility and attack rates are higher in children. This is the opposite of Covid-19.

“Data on the benefit of school closures in the Covid-19 outbreak is limited but what we know shows that their impact is likely to be only small compared to other infection control measures such as case isolation and is only effective when other social isolating measures are adhered to.”

He added: “With nearly 90 per cent of the world’s students (more than a billion-and-a-half young people) out of school, more data and robust modelling studies are urgently needed to help us identify how countries can, in time, safely return students to education.”

Geoff Barton, general secretary of the Association of School and College Leaders, said: “These findings demonstrate that the government must keep the decision to close schools under review.

“It is certainly the case that a prolonged shutdown will damage the education of children and it is likely that those from disadvantaged backgrounds will suffer the most.”

He added: “However, it will be difficult to fully reopen schools while significant numbers of staff have to self-isolate in line with public health advice.”

Robert Dingwall, professor of sociology at Nottingham Trent University, said: “This work suggests that UK schools could, and should, begin to reopen as soon as practicable after the initial wave of cases has passed through.

“The biggest risk may come from gatherings of parents, grandparents and other carers at the school gate rather than anything that happens inside.”

Professor Neil Ferguson, from Imperial College London and author of a report which warned of mass deaths if the UK did not introduce strict controls, said: “While school closure as a measure on its own is predicted to have a limited effectiveness in controlling Covid-19 transmission, when combined with intense social distancing it plays an important role in severing remaining contacts between households and thus ensuring transmission declines.

“While this new paper reviews some of the modelling our group undertook of school closure for less intensive mitigation, it did not include our results for school closure in combination with other lockdown measures.”

A government spokesperson stated: “The decision to close schools was taken in line with scientific advice on how to limit the spread of the coronavirus. We asked most children to stay at home in order to protect the NHS and save lives.

“Schools will remain closed until further notice, except for children of critical workers and the children who are most vulnerable. We will reopen schools when the scientific advice indicates it is safe to do so.”

Press Association