Coronavirus: Closing schools could increase death toll by prolonging outbreak, scientists say as they warn against short-termism

Result of modelling experiment not a prediction but indicator of how suppressing epidemic only kicks can down the road, says professor

Around 18 per cent of state scondary schools were not fully open on 1 October, DfE figures show (Getty Images/iStockphoto)

Researchers have warned against short-termism in combatting Covid-19 as they published a study suggesting closing schools during the coronavirus crisis may increase the overall death rate by prolonging the pandemic.

The work casts doubt on the efficacy of tough, universal lockdown measures in reducing the death toll amid the fraught debate surrounding herd immunity.

University of Edinburgh experts have newly analysed an Imperial College London study that predicted hundreds of thousands of deaths from Covid-19 if the government took no action to stop its spread. Report Nine, as it was known, led to the all-encompassing lockdown earlier this year.

Now researchers from the University of Edinburgh have reassessed the model used, examining and reproducing the main results in Report Nine using the information available at the time in order to understand how decisions made early in the pandemic could play out.

They specifically looked at the effect of school closures; Imperial's team found that while closing schools reduced the reproduction number of Covid-19, it also raised the number of deaths.

The Edinburgh researchers replicated these findings using the “CovidSim” model of 70 million simulated people carrying out everyday activities. Writing in the British Medical Journal, they said: "In the absence of an effective vaccine for Covid-19, school closures would result in more overall deaths than no school closures."

However, this result, which refers to school closures in March, is predicated on a large, unmitigated second wave of infections following the modelled lockdown. In reality, the government is reimposing restrictions to fight that new spread.

It is important not to see the “headline result” as a prediction, said Mark Woolhouse, professor of infectious disease epidemiology at the University of Edinburgh.

He added: "Nonetheless, this counterintuitive result does shed some light on the current debate about whether to allow herd immunity to build up in age groups that rarely experience severe consequences of infection.

"Though the modelled scenario may be unrealistic, it does illustrate the general principle that, of itself, lockdown solves an immediate crisis without providing a long-term solution. In trying to keep the epidemic suppressed, we risk a recurrent cycle of restrictions of one form or another.

"Perhaps the key lesson that should be drawn from this study is the warning that if we allow short-term thinking to dictate our response to Covid-19 then we may not make the best decisions for minimising the public health burden over the longer term."

The study came as research by the Labour Party suggested that second-wave infection rates had increased in 19 of the 20 areas of England in which they had been imposed. Sir Keir Starmer said during PMQs on Wednesday: “The prime minister can’t explain why an area goes into restrictions. He can’t explain what the different restrictions are, and he can’t explain how restrictions end. This is getting ridiculous.”

Still further crackdowns are looming over northern England – including, potentially, the closing of pubs and restaurants as has taken place in Scotland.

The University of Edinburgh study also found that social distancing is a more effective tool at reducing deaths when only employed by people over 70, compared with among the general population, the institution said.

The authors wrote: "The findings of this study suggest that prompt interventions were shown to be highly effective at reducing peak demand for intensive care unit (ICU) beds but also prolong the epidemic, in some cases resulting in more deaths long-term.

"This happens because Covid-19 related mortality is highly skewed towards older age groups. In the absence of an effective vaccination programme, none of the proposed mitigation strategies in the UK would reduce the predicted total number of deaths below 200,000."

They point out that when the interventions are lifted, there is still a large proportion of the population susceptible and a substantial number still infected. "This then leads to a second wave of infections that can result in more deaths, but later," they wrote.

The authors said that the final death toll from Covid-19 depends largely on the age of those infected and not the overall number of cases. They added that the modelling suggests that there needs to be some sort of prioritisation of aims in tackling the crisis - reducing the case numbers, reducing the death toll or reducing the burden on intensive care units.

Graeme Ackland, professor of computer simulation from the University of Edinburgh's School of Physics and Astronomy who led the study, said: "In the short-term, closing schools contributed to reducing the severity of the first wave, to the extent that Nightingale hospitals were not needed, but the decision has left us more vulnerable to subsequent waves of infection.

"Mitigating a Covid-19 epidemic requires very different strategies for different age groups and a different strategy from an influenza epidemic, with more focus on shielding elderly and vulnerable people."

A spokesperson for Imperial's Covid-19 Response Team, which produced Report Nine, said: "This provides further independent confirmation that Imperial's modelling in March was robust, reproducible and sound in its conclusions.

"We welcome this independent analysis of Report Nine as we continue to advance our understanding of the early epidemic."

A government spokesperson said: "At every stage of our response we have been guided by the advice of experts and took decisive action from the outset to support the NHS and save lives.

"We have been doing everything we can to ensure the most vulnerable people in our society are protected. This includes testing all residents and staff in care homes, providing over 228 million items of PPE, ring-fencing over £1.1bn to prevent infections in care homes and making a further £3.7bn available to councils to address pressures caused by the pandemic."

Additional reporting by Press Association