March.27.2020

School closures and COVID-19 – what the research says we should be doing

By Rachel Wilson

Schools in Queensland, South Australia and Western Australia will go pupil free from Monday, taking only children of essential workers. I have been having a close look at the available research and evidence on school closures and the COVID-19 pandemic, and I am wondering why there is no urgent national call to close all Australian schools to pupils, and certainly why it has taken this long for state authorities to begin to shut down their schools.

Internationally there are now 140 countries with full national school closures, if there is evidence to support keeping schools open, then it is unknown to large swathes of the planet.

Research suggests the potential of school closures to provide reductions in disease and mortality is moderated by the timing of school closures. Early closures, particularly early reactive (in response to school cases) and gradual closures, are associated with stronger positive effects. This is evident even in recent, hot-off-the-press, COVID19 research from France.

Leaving closure until things look grim, near or after the epidemic peak, means that they are likely to be less effective in slowing the disease.

School closures do bring very substantial costs to the economy, and risks to the education and welfare of many children. Some also argue that they curtail our response to the virus, by adding additional burdens on parents who may be working against the pandemic.  These considerations, and strategies to mitigate them, must be weighed against the potential of school closures to delay and reduce virus transmission.

However, if you delve into the research evidence outlining the effects of school closures – and extrapolate the research effects to the current mortality rates for the COVID19 epidemic the number of lives that could be saved is staggering.

Research evidence on school closures and novel influenza outbreaks

There are two recent systematic reviews on this. A systematic review is a comprehensive trawl and review of research evidence. Most of these reviews also apply research quality criteria to the research found, so that only research that meets a minimum quality benchmark can be considered in the synthesis of evidence on the topic at hand.

The first systemic review I want to tell you about was published in 2018. It examined school closure in response to novel flu epidemics and included recent studies examining the impact of school closures on the 2009 Novel Flu epidemic in Mexico, the US and elsewhere. This review examined 668 research articles and synthesised findings for 31 high quality studies. Primary conclusions of the review are:

  • An average 30% reduction in the peak of the epidemic
  • School closure BEFORE the epidemic peak reduces the overall burden of the epidemic
  • Earlier implementation can delay the epidemic peak as well as reduce it.
  • The longer the school closure the longer the delay on the epidemic peak.
  • School closure is correlated with virus ‘attack rate’ and a longer infectiveness duration.

Another review examined different closure strategies and performed a model-based analysis of the effectiveness of four types of school closure for influenza outbreaks. Closure models ranged from the nationwide closure of all schools at the same time, to county/district closures, to reactive (in response to school cases) and gradual closures (starting from class-by-class, then grades and finally the whole school).

The review found that, under specific constraints on the average number of weeks lost per student, reactive school-by-school, gradual, and county-wide closure gave comparable outcomes – all provided infection attack rate reduction, peak incidence reduction and peak delay. Optimal implementations for flu required relatively short closures, with just a one-week closure enough to break the transmission chain without unnecessary disruption.

Optimal length of closure might be very different for COVID19 given its long, two-week, latency, high transmission rate and pandemic status. However, the researchers broadly conclude:

“policy makers could consider school closure policies more diffusely as response strategy to influenza epidemics and pandemics, and the fact that some countries already have some experience of gradual or regional closures for seasonal influenza outbreaks demonstrates that logistic and feasibility challenges of school closure strategies can be to some extent overcome”.

In just published research on COVID19 in France, it was found:

school closure alone would have limited benefit in reducing the peak incidence (less than 10% reduction with 8-week school closure for regions in the early phase of the epidemic). When coupled with 25% adults teleworking, 8-week school closure would be enough to delay the peak by almost 2 months with an approximately 40% reduction of the case incidence at the peak. This is critical to reduce the burden on the healthcare system in the weeks of highest demand. Moderate overall reduction of the final attack rate (15%) would also be achieved.”

The same research found:

Real-time evaluation of currently adopted measures in France, as well as lessons learnt from the experiences of other countries implementing stricter policies (e.g. closing commercial activities and forbidding all sport and leisure activities, as in Italy and Belgium) will become crucial in the next few weeks to inform interventions and recommendations adapted to the evolving epidemic situation in the country.

And:

If school closure is stopped too early, a rebound effect with an acceleration in the generation of new cases is likely to occur, as known from previous studies6. Here we assumed telework to last for the full simulation; its feasibility still needs to be assessed. If telework [*] is stopped after a certain period, a rebound effect is expected in this case too, due to the increase of social contacts.

*‘Telework’ is working from home using technology.

Partial and full closures

But at the moment across Australia we only have partial school closures in state schools, even though many private schools fully transitioned their teaching to online weeks ago. In NSW, for example, the Premier has asked parents to keep children at home if they could but baulked at closing schools down. At the moment NSW state school parents are choosing whether to send their children to school or not.

So, at a national level what is happening in Australia amounts to a partial school closure for our nation, which according to UNESCO makes Australia one of just 12 countries with such an approach (including the USA). However, there are now 140 countries with full national school closures, impacting over 80% of world’s student population.

These countries have taken the option to close all their schools in order to contain the pandemic, even countries that currently observe very few confirmed cases of COVID19 (like our neighbour Timor which has only 2 as I write this).

Given that some 140 countries have already tackled the logistical difficulties with national closures, the question remains: Why is Australia not embracing the medical benefits of school closures?

It could be too late for gradual and reactive closures

The immediate problem In Australia is that it may already be too late for reactive and gradual school closures.

This is because widespread proactive closures are now probably needed. As social scientist and physician at Yale University, Nicholas Christakis, tells us – community spread cases in schools “are the canary in the coalmine…when you detect one case there are probably dozens or hundreds of others.” We already have some of these in our schools, but our governments have not heard the canary.

Experts, including thousands of Australian doctors, recommend that community spread cases in schools mean that regional or national proactive school closures are needed. Given the unprecedented threat posed by COVID19, the current voluntary approach, where parents are encouraged but not required to keep their children at home, is a risk of enormous magnitude.

Proactive district, state and national closures, as Christakis tells us, have been shown:

“ …to be one of the most powerful nonpharmaceutical interventions that we can deploy. Proactive school closures work like reactive school closures not just because they get the children, the little vectors, removed from circulation. It’s not just about keeping the kids safe. It’s keeping the whole community safe.”

The example of the Spanish Flu in 1918

Previous school closures have been associated with a two-thirds reduction in death toll.

Research from the worlds’ last great pandemic, the Spanish flu in 1918, examined proactive versus reactive school closures and the timeliness of school closures relative to the growth of the epidemic. They found proactive school closing saved many lives. St. Louis closed the schools about a day in advance of the epidemic spiking, for 143 days. Pittsburgh closed 7 days after the peak and only for 53 days. And the death rate for the epidemic in St. Louis was roughly one-third as high as in Pittsburgh.

We must close all schools in Australia before the spike in the epidemic. Whistle-blowing doctors argue this is a critically important part of using ““every mechanism to ‘flatten the curve’ “ and will buy them time to equip and cope with the rise in cases.

Rachel Wilson is an Associate Professor at the University of Sydney. Rachel is currently the program director for the Master in Education – Management & Leadership program. She has particular expertise in educational assessment, research methods and program evaluation. As such she has broad interests across educational evidence, policy and practice. She is interested in system level reform and innovation and has been involved in many university and education sector wide reforms.

Republish this article for free, online or in print, under Creative Commons licence.

3 thoughts on “School closures and COVID-19 – what the research says we should be doing

  1. Rob says:

    SA schools start their pupil free days on Monday 6th April not Monday 30th March

  2. Colin Kenworthy says:

    Rachel,
    Thanks and congratulations on this article.

  3. Christopher McCaw says:

    There may indeed be strong arguments for school closure in the current context. However there needs to be much more caution in extrapolating from influenza-focused research & modelling to the Covid-19 context. Current data shows that, unlike with influenza, young children i) are not strong vectors of transmission, and ii) are not experiencing a high degree of symptom and mortality burden. These key differences between influenza and Covid-19 mean that the inferences drawn in this article about school closure are by no means straightforward.

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