How schools can safely reopen during the pandemic

Children in South Korean schools have lunch in silence, facing plastic screens separating them from their friends¹. They wear masks except when practicing social distancing in the playground. And their temperatures are checked twice a morning – first at home and again at the school gates.

This could be the new reality for millions of children around the world. Summer vacation is coming to an end in the northern hemisphere, and in places like the United States, the United Kingdom and some European countries that closed schools during the coronavirus pandemic, governments are wondering when and how to open schools. A growing number of studies show that there are ways to do this safely. The key is hygiene and physical distancing vigilance, a rapid public health response to stop the spread of any infection and, most importantly, low levels of viral spread in the community.

“Some countries in Asia, especially South Korea, offer a good model of how schools can provide face-to-face education during the pandemic,” says Zoë Hyde, epidemiologist at the University of Australia- Western in Perth.

But researchers say if schools are opened before community transmission reaches low levels, cases will increase.

High risk environment

Schools can be high-risk places, says Young June Choe, a pediatrician and epidemiologist at Hallym University in Chuncheon, South Korea. Children are often crammed into poorly ventilated rooms for eight hours or more, he says. And there’s a lot of mixing, because the kids come from all over the neighborhood, some on public transport, and often with their parents in tow.

Earlier in the pandemic, it emerged that children may interact with the virus differently than adults. Since the children had milder symptoms, it was speculated that they might be less contagious. But now there is evidence that children can transmit the virus to other people, especially those who live in the same household.^2,3. Several studies show that once children are infected, they are not less so⁴.

“If schools are reopened in areas with high levels of community transmission, major epidemics are inevitable and deaths will occur in the community as a result,” Hyde says. Evidence of this can be seen in the sporadic outbreaks and outbursts that have occurred before, including those at a high school in Israel and a camp in the United States.

Low community spread

Studies in South Korea¹, Europe and Australia⁵ show that schools can safely open when community transmission is low. Children in South Korea returned to their classrooms in mid-May, when daily confirmed cases fell below 50, or about one case per million people. Even with such low transmission rates, the government has introduced measures to control the spread of the virus, such as the phased opening of schools, starting with high schools and then middle schools. In large schools, or those located in regions where the number of cases was increasing, only a part of the students attended. When someone tested positive, the education went back online.

An analysis by Seoul researchers that has not yet been peer reviewed found no sudden increase in COVID-19 cases in children aged 19 and under in the 2 months following the reopening of schools¹. And government data shows that only 1 of 111 school-aged children who tested positive between May and July contracted the infection at school. Most have been infected by family members or elsewhere. “The take home message is that with the right policies, we can control transmission in schools in a context of low community transmission,” Choe says. “There is no special recipe that makes Korea unique.”

A survey by the European Center for Disease Prevention and Control also found that reopening schools in several European countries from mid-May has so far not been associated with a significant increase in community transmission.

The state of New South Wales (NSW) in Australia partially closed schools at the height of the state’s outbreak in March, but kept daycare open. Kristine Macartney, director of the Australian National Immunization Research and Surveillance Center in Sydney, and her colleagues analyzed data from schools and daycares between late January and early April. Schools remain open to children of health workers or to those who have no alternative.

During the study period, the state recorded an average of 193 cases per day – 24 per million people – but 58% of the cases involved travelers returning from abroad. Macartney and colleagues found that only 25 of 7,700 schools or daycares reported primary infection during the study period⁵. Of these cases, only four establishments had continuous transmission.

Macartney stresses that the findings must be seen in the context of the state’s strong public health response. NSW maintained high levels of population testing, promptly identified cases and implemented contact tracing, and its borders were closed, with strict enforcement of quarantines. “If the transmission were to happen out of control in the community, we’re sure it would spill over into schools,” Macartney says, noting that in a recent outbreak of cases in neighboring Victoria, hot spots have been identified in schools. “This virus will take advantage of any loophole in the armor,” she said.

Crowded classrooms

In places where there is community spread, schools and camps have become the sites of major epidemics. The virus swept through an overnight camp in the US state of Georgia in mid-June. On the first day of the camp, Georgia reported 993 new cases of COVID-19. Campers slept in cabins in groups of up to 26 people, did not need to wear masks, and sang and cheered every day. A staggering three-quarters of 344 participants tested tested positive for SARS-CoV-2⁶.

Another major outbreak was detected at a high school in Jerusalem, Israel, 10 days after all schools reopened in mid-May. There were around 127 reported cases per day in the country at the beginning of May, when some children started returning to school, or 15 cases per million population.

With temperatures exceeding 40 ° C, the teens sat in air-conditioned rooms with more than 30 other classmates without masks. The epidemic affected 153 students and 25 staff, as well as 87 siblings, relatives and friends of those affected.⁷.

The school environment can also increase the risk of community spread. In mid-March, a large school in Santiago, Chile experienced a major outbreak just nine days after the country detected its first case of COVID-19. The school had more than 30 children in a class and had been very busy organizing parent-teacher meetings. Researchers detected anti-SARS-CoV-2 antibodies in 10% of students and 17% of staff when tested about two months later⁸.

School outbreaks in Israel and Chile suggest large class sizes may play a role in transmission in schools, says Edward Goldstein, infectious disease epidemiologist at the Harvard TH Chan School of Public Health in Boston, Massachusetts.

Schools should implement reasonable distancing measures, dividing the day into morning and afternoon shifts to reduce the number of children in a classroom, for example, and preventing parents and teachers from leaving. congregating at school entrances and exits, says Miguel O’Ryan, a pediatric infectious disease researcher at the University of Chile in Santiago who led the Santiago school’s study.

If schools reopen in areas with high community transmission rates, being diligent in masking, Class size, handwashing, testing and tracing will be especially important, says Katherine Auger, a pediatric researcher at Cincinnati Children’s Hospital Medical Center in Ohio.

“If we go back to schools as they were before, we’ll be in trouble,” she says.