Researchers in the UK have warned that given how future waves of coronavirus disease 2019 (COVID-19) seem to be inevitable, it is likely that schools will be put under further pressure to close.
The team says the negative impacts school closures could have on children and society at large should be appropriately considered before deciding whether to proceed.
The part that children play in the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) the agent that causes COVID-19 – remains unclear.
However, current evidence suggests that unlike other respiratory viruses, the educational setting only plays a small part in SARS-CoV-2 transmission once control measures have been implemented.
The researchers say pandemic mitigation measures that impact children's well-being should not be implemented unless there is sufficient evidence that this would help.
Matthew Snape (University of Oxford) and Russel Viner (University College London) have expressed their views in an opinion piece recently published in the journal Science.
Children had been expected to be a key component in transmission
The unprecedented and ongoing spread of SARS-CoV-2 has posed significant challenges in terms of managing the care of children and adolescents worldwide.
The widespread closures of schools in response to the COVID-19 pandemic reflected the reasonable assumption, given previous outbreaks of respiratory viruses, that children would play a key part in transmission.
However, a growing body of evidence has suggested that this is not necessarily the case.
Unlike the usual pattern of respiratory viral infection, children and adolescents are at a significantly lower risk of developing symptomatic COVID-19, compared with all other age groups.
However, one concern is potential viral shedding among asymptomatic children and schools becoming pools of viral circulation from which transmission to pupils' homes and beyond could occur.
Given that schools have been closed alongside the implementation of various other lockdown measures, it has been difficult to gauge whether schools' closure provides any benefit over other interventions.
Evidence suggests onward transmission through children is minimal
"Evidence from contact-tracing studies suggests that children and teenagers are less susceptible to SARS-CoV-2 infection than adults," writes the team.
Multiple studies have demonstrated only minimal onward transmission of SARS-CoV-2 in both primary and secondary schools. Following the re-opening of primary schools in the UK, for instance, only 1 of 23,358 nasal swabs taken from children in June 2020 had detectable levels of the virus.
Furthermore, recent surveys conducted in various European countries found that the re-opening of schools in April and May had no significant effect on community transmission. The number of infections generally continued to fall once schools had re-opened.
"Relative to their risk of contracting the disease, children and adolescents have been disproportionately affected by lockdown measures," Snape and Viner write. "Advocates of child health need to ensure that children's rights to health and social care, mental health support, and education are protected throughout subsequent pandemic waves."
The upcoming months will be important for assessing the effectiveness of interventions
Examples of the mitigation measures being implemented as schools re-open across the Northern Hemisphere include creating separate cohorts or "bubbles" of pupils with minimal interaction, the use of face masks in crowded areas, and regular screening of pupils and staff.
The upcoming months will provide a valuable window of time to assess which of these interventions are the most effective at reducing transmission. This will help create a standard "best practice" that ensures young people's rights to an education are not infringed while also protecting them in the broader community.
However, the researchers say there will inevitably be cases of infected pupils attending school and that some school outbreaks are likely.
The potential effects of keeping schools closed
Nevertheless, keeping schools closed while the retail and hospitality sectors re-open is difficult to justify, given the indirect negative impacts this could have on young people and society, says the team. Estimates so far suggest that the impact on education could lead to one-quarter of the nations' workforce being less skilled after the mid-2020s and the loss of billions of dollars of wealth.
Other risks to children include the potential re-emergence of diseases such as measles as a result of disruption to vaccination programs and an increase in accidental and nonaccidental injuries in the home due to children being less visible to protection services.
The adverse effects on young people's mental health should also be considered, write the researchers.
"For example, preliminary evidence suggests that deaths by suicide of young people under 18 years old increased during lockdown in England," they say.
There is now an evidence base on which to base decisions
However, there is now an evidence base on which to base decisions, and school closures should be undertaken with trepidation given the indirect harms that they incur, says the team.
"Pandemic mitigation measures that affect children's well-being should only happen if evidence exists that they help because there is plenty of evidence that they do harm," the authors conclude.