This evidence synthesis has been compiled by members of the CITF Secretariat and does not necessarily represent the views of all CITF members.

By Kristin Davis

Sweden takes a different approach to COVID-19 restrictions in schools

In March 2020, schools around the world closed their doors, the boisterous youthful chatter of classrooms and schoolyards replaced by an eerie stillness that will come to characterize the first weeks of the COVID-19 pandemic. Now, nearly a year later, numerous classrooms have resumed in-person  instruction  with  major adjustments to day-to-day activities, such as increased hand washing, physical distancing and mask wearing, all in the hopes of keeping the spread of SARS-CoV-2, the virus that causes COVID-19, at bay. Both academic and government circles are asking the question “does the benefit to children’s learning and development outweigh the risks of increased viral spread by keeping schools open?

Last spring, Sweden was one of the few countries (including Nicaragua and Taiwan) to not cancel in-person classes for students in grades 9 and lower, whereas upper-secondary school (grades 10-12) shifted to remote learning. For the most part, in-person learning continued without major change, deprived of precautionary measures such as class size reductions, mask wearing and even isolation of known or suspected cases of COVID-19. Acting as a type of ‘uncontrolled natural experiment’, Sweden’s decision to partially close secondary schools offered the unique opportunity to measure the impact of school closure on the transmission dynamics of SARS-CoV-2.

In an article published this month, Swedish researchers found that the decision to keep schools open doubled the incidence of PCR-confirmed SARS-CoV-2 infection among lower-secondary school teachers (grades 7-9) compared to upper-secondary school teachers, the latter teaching remotely. This pattern is consistent with the observation that a teacher’s risk of infection increases with student age. Indeed, teachers of lower-secondary schools were found to be the 7th most at-risk occupational group (excluding healthcare workers) in Sweden, following police officers, social workers and taxi drivers. Furthermore, the authors note that 79 of the ~39,000 lower-secondary teachers in Sweden were hospitalized with severe COVID-19 and one died. Using age-specific case rates, they estimate that as many as 33 of these hospitalizations might have been avoided if schools had reverted to remote learning.

Most notably, the study showed that the increased risk of infection among teachers in lower-secondary extended to their partners, who experienced a higher incidence of PCR-confirmed SARS-CoV-2 infection compared to the partners of upper-secondary teachers. Remarkably, parents of students in lower- or upper-secondary schools did not show a big increase nor difference in rates of infection. The extent to which the heightened risk to teacher’s partners is due to student-teacher or teacher-teacher spread is still up for debate. The authors go on to report that keeping grades 7-9 in session had a minor impact on the overall transmission of the COVID-19 virus in the community; however, what this report does make clear is that teachers, particularly those teaching adolescents, are at an increased risk of infection. With the omnipresent threat of emerging variants, the implementation of strict nonpharmaceutical interventions such as personal protective equipment (PPE) are imperative for optimal control of COVID-19 in schools. Likewise, the prioritization of teachers in the queue for vaccination needs to be carefully considered.

Also published this month was an elegant modelling study  of various school reopening scenarios based on the lived experience of an epidemic in the French region of Île-de-France during the first wave of the pandemic. Researchers show that reopening all levels of schooling (pre-, primary, middle and high school) at once may push ICU capacity to its limits, while the progressive reopening of pre- and primary schools first, followed by middle and high schools, in combination with strong universal adoption of nonpharmaceutical interventions, can allow the safe reopening of schools while keeping the pandemic under control. Although clearly distinct, both these studies indicate that the risk of keeping schools open may not be symmetric across settings, and a phased reopening approach starting with pre- and primary schools might be the best approach to ensuring safety for all individuals involved in the education sector.

How the CITF is helping to understand SARS-CoV-2 spread in Canadian schools

The COVID-19 Immunity Task Force (CITF) is funding several initiatives tracking the spread of the COVID-19 virus in various educational sectors. The EnCORE project currently underway in the Greater Montreal Area is studying the incidence of SARS-CoV-2 infection among children and adolescents in daycares, elementary and high schools. The SPRING study is aiming to understand how many children and young adults in British Columbia have been infected with SARS-CoV-2. More recently, the CITF announced the roll-out of two studies looking at SARS-CoV-2 transmission and immunity on two different university campuses and another CITF-funded university campus study will be revealed later this week. The CITF will also soon announce the funding of three additional studies looking at SARS-CoV-2 transmission, immunity and vaccine effectiveness among teachers from various educational settings across Canada. These studies will help to shed light on the extent of SARS-CoV-2 transmission in Canadian schools and its impact on the health and well-being of students, teachers and educational personnel.