Variation in SARS-CoV-2 seroprevalence across districts, schools and classes: baseline measurements from a cohort of primary and secondary school children in Switzerland.

Objectives: To determine the variation in SARS-CoV-2 seroprevalence in school children and the relationship with self-reported symptoms.

Design: Baseline measurements of a longitudinal cohort study () from June to July 2020.

Setting: 55 schools stratified by district in the canton of Zurich, Switzerland.