Studies conducted before mass vaccination campaigns began have reported proper and consistent facemasking by students and staff in school settings are associated with reduced incidence of school-associated transmission or seropositivity.
Fewer studies have reported efficacy of facemasking in the post-mass vaccination period in school settings. The studies available report, however, school-associated transmission were lower, less than 1% secondary attack rate in schools.
Studies of school-associated COVID-19 cases find community exposure to SARS-CoV-2 and/or noncompliance with multiple mitigation measures (e.g. facemask policies, distancing, non-isolation, etc) are key factors of clusters and outbreaks in children.
Badea, A; Groot, G; Muhajarine, N; Howell-Spooner, B; Young, C. What is the evidence for the effectiveness of universal mask use in the pediatric population? 2021 Sep 30, Document no.: EOC210901 RR. In: COVID-19 Rapid Evidence Reviews [Internet]. SK: SK COVID Evidence Support Team, c2021. 14 p. (CEST rapid review report).