LAUSR

© Author(s) (or their employer(s)) 2023. Reuse permitted under CC BYNC. No commercial reuse. See rights and permissions. Published by BMJ. During the early phase of the pandemic, school closures were one of the nonpharmaceutical interventions (NPIs) implemented globally to reduce transmission. Given that SARSCoV2 will continue to circulate for years to come, school closures may be debated again. As familiar respiratory viruses have returned, their combined pressure alongside COVID19 caused renewed discussion of closures in the UK and initiation of remote learning in areas of the USA in the winter of 2022. 2 This suggests that debates around school closures will continue into the future. According to the Oxford COVID19 policy tracker, school closures around the world were rapid and nearly uniform in March 2020. In contrast, the reopening process was much more variable, with different countries using different metrics and criteria to reopen. According to our analysis, the variability in duration of school closures between January 2020 and December 2021 was extreme. A handful of countries had zero days (including Burundi, Tajikistan and Turkmenistan), while Brazil, Panama, Peru and Ukraine required some level of closure for a total of 660 days, and Saudi Arabia for 663 days (figures 1 and 2). These differences highlight the lack of consensus about the efficacy of school closures on reducing COVID19 deaths. At the start of the pandemic, the justifications of closing schools included a combination of ‘first principles’ (anything reducing social contact is valuable) and drawing on previous evidence based on influenza outbreaks. Such interventions have their origins in complex historical precedent, social and medical circumstances. During the 1918 influenza pandemic, school closures were implemented and heavily debated, with experts arguing that harms of closing schools including negative impact on their development with little effect on influenza transmission. Underlying assumptions driving these decisions include children having a larger number of contacts on average than most adults, some school buildings containing poorly ventilated, small rooms which would be considered highrisk environments for transmission and the principle of protecting families (alongside concerns about potential increased risk to educational staff). Given the emergence of the significant economic, social and health cumulative burden related to prolonged school closures, the argument to further deploy them is weak. Based on current evidence, we argue the harm of closing schools now clearly outweighs the benefits of reducing transmission.