Question: Does reopening schools in the pandemic increase COVID-19 incidence and mortality?
Findings: On average, there was no systematic association between school reopening and COVID-19 incidence or mortality in So Paulo State, up to 12 weeks after reopening. This was also the case for schools in most vulnerable conditions. Aggregate mobility was already high before the school reopening and did not significantly increase afterwards.
Meaning: Results imply that reopening schools under appropriate protocols in developing countries during the pandemic is unlikely to affect the aggregate number of cases or deaths when counterfactual mobility is already high.