Do school closures really help reduce the spread of the coronavirus?

An empty classroom.
(Image credit: Shutterstock)

Schools in more than 100 countries, including most in the U.S., are closed to aid in social distancing during the COVID-19 pandemic, but a new review study questions how much these closures will really help to reduce the disease's spread.

The authors, from University College London, reviewed 16 studies on the effect of school closures during coronavirus outbreaks, and concluded that "evidence to support national closure of schools to combat COVID-19 is very weak." In contrast, the harms of school closures, including high economic costs, are more clear-cut.

Policy makers should be aware of the uncertainty of evidence supporting school closures and may need to consider "other less disruptive social-distancing interventions in schools," the authors wrote in their paper, published online April 6 in the journal The Lancet Child & Adolescent Health. These might include keeping schools open only for the children of essential workers, staggering school start times and lunch breaks across different grades, increasing the space between students in classes or closing playgrounds.

Related: 20 of the worst epidemics and pandemics in history

Weak evidence 

Most of the scientific data on the effects of school closures comes from studying seasonal or pandemic flu, and some of this research does show a benefit. 

In particular, studies on flu suggest the effects of school closures may be greatest when viruses have a low transmissibility and infect children at higher rates than adults. (When a virus doesn't transmit that easily, school closures by themselves may reduce contact in the population enough to reduce the size of the epidemic.) 

But this doesn't seem to be the case for the new coronavirus, SARS-CoV-2, which spreads more easily than the flu and causes less severe disease in children than it does in adults, the authors said. (Although it's unclear how big a role children play in spreading the new coronavirus, they may be less likely to spread the disease by coughing and sneezing since they tend to develop mild or asymptomatic cases, the authors said.)

In the new study, the authors reviewed research on the effects of school closures during the SARS outbreak of 2002, as well as research on school closures and social distancing in response to COVID-19. They looked at both studies published in peer-reviewed journals and studies that haven’t yet gone through that process but have been published on so-called preprint websites. 

Studies on the SARS outbreak largely found that schools did not play a role in transmission of the virus, and so school closures didn't contribute to control of the outbreak, the authors said.

Recent studies on COVID-19 in China have found that a "package of social-distancing measures" that includes school closures were effective in reducing the size and peak of the outbreak there. But critically, these studies didn't separate the effects of school closures from other social-distancing measures, the authors said, so the true effect is unclear.

The authors found only one study that looked at the effect of school closures separate from other social-distancing measures. This study, which modeled the effect in the U.K. population, suggested that school closures by themselves were predicted to reduce COVID-19 deaths by only 2% to 4%, which was much lower than the effect of other measures, such as isolating infected cases.

'Urgent need' for research 

There is an "urgent need" to better study the effects of school closures during COVID-19, as well as how countries that have already shut schools and offices can "safely return students to education and parents to work," the authors said. 

More studies are also needed to figure out how big of a role children play in transmitting COVID-19, they said.

"Education is one of the strongest predictors of the health and the wealth of a country's future workers, and the impact of long-term school closure on educational outcomes, future earnings, the  health of young people and future national productivity has not been quantified," they concluded.

Originally published on Live Science.   

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Rachael Rettner

Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.

  • Witold Ferens
    This is very strange reasoning.
    It is well established that:
    1) children are likely to have asymptomatic infection;
    2) asymptomatic people can spread the infection;
    3) virus spreads easily in closed quarters.

    So you would want to put a crowd of children in close proximity with adults, some of whom may be in high risk group? And who will be teaching these kids when teachers get sick?

    I am truly puzzled at the argument presented in this text.
  • award
    I'm thinking the same thing. It reads as if the author didn't really think this through. I would add to your comment, students will be taking the virus home and now their parents will take it to work. Then who will be working? Also, stagger school start times? The bus routes would be unfeasible. Teachers would be expected to work 12 hour days. Without a doubt, the author did not think before typing.
  • Honey West
    I agree with the comments here. I don't know who wrote this article, but they haven't any common sense. If school closures didn't matter, why did Wuhan close them? Why do they remain closed even after ending the lockdown? Children are notorious for bringing colds home to their families. Every child who catches will be able to spread the virus to everyone in an exponential manner. Many older workers work as lunchroom personnel. I mean, what if there is a baby sibling at home and Susie Q. brings home the virus? What if grandma is living at home, too? Asymptomatics do spread the disease, and it incubates before symptoms even appear. This is total jabberwocky. It should have been run on
    "April FOOL'S Day." There haven't been studies, because they are not needed. It's common sense.
  • retired teacher
    I agree with the previous comments. Having just retired as a high school teacher, it would be highly unlikely to ask students to keep social distancing. Kids like to converse and share (on almost everything) and they can't say no to their peers. Then with recent teaching techniques, such as cooperative learning, grouping, and with class sizes spacing is is unlikely. Also observed, is the lack of hygiene exhibited by some students.
    On the bright side (?), parents now get to spend more time with their children!!!!
  • kilic44
    Really!! I am shocked with this piece! by a senior writer??
    The argument, evidence, reasoning and logic are so stupid then we have to argue and explain here that it is nonsense. Livescience editors should have done a better job..
  • Urquiola
    Perhaps kids have a milder Coronavirus disease than adults, but in the trip back and forth home they can spread the V-19 to people who can have a severe disease. it is known that kindergarten kids have higher mortality and morbidity than those at home; once a bit taller, kids are not that feeble, but the lessons is at school, they get diseases at any age. Blessings +
  • Mauian1
    Whoever wrote this has never worked in a school. Schools are big germ tanks much like an airplane. Why practice social distancing for everything, then say it isn't necessary in a school? Think about how restaurants are reconfiguring their seating. It isn't possible to do that when there are 20+ students in a class. Also, if students /teachers /staff become ill, they would have a good legal case against the school for "negligence" This is another example of how non-educators think decisions can be made because there's reseach out there to "support" what they want it to say. Well, a lot of the research for this article is also coming from non-educators. That pretty much makes all the claims for opening the schools invalid. There would be more truth to the article if they would have interviewed a Superintendent or Principal and used that information instead.
  • schoollog
    School should remain close and students should try out different measures like using software for studying Education is the key source of everything <a href="">Schoollog</a>