During the COVID-19 pandemic, widespread school closures were implemented globally based on the assumption that transmission among children in the school environment is common. However, evidence regarding secondary infection rates by school type and level of contact is lacking. Our study estimated the frequency of SARS-CoV-2 infection in school settings by examining the positivity rate according to school type and level of contact by using data from a large-scale school-based PCR project conducted in Okinawa, Japan, during 2021–2022. Our results indicate that, despite detection of numerous positive cases, the average number of secondary infections remained relatively low at ≈0.5 cases across all types of schools. Considering the profound effects of prolonged closures on educational access, balancing public health benefits against potential long-term effects on children is crucial.

在 COVID-19 大流行期间，基于学校环境中儿童之间传播很常见的假设，在全球范围内实施了广泛的学校关闭。然而，缺乏关于学校类型和接触水平的继发感染率的证据。我们的研究通过使用 2021 年至 2021 年在日本冲绳进行的大型学校 PCR 项目的数据，根据学校类型和接触水平检查阳性率，估计了学校环境中 SARS-CoV-2022 感染的频率。我们的结果表明，尽管发现了大量阳性病例，但所有类型的学校的平均继发感染人数仍然相对较低，为 ≈0.5 例。考虑到长期关闭对教育机会的深远影响，平衡公共卫生利益与对儿童的潜在长期影响至关重要。