  During the COVID-19 pandemic, many countries opted for strict public health
measures, including closing schools. They have now started relaxing some of
those restrictions. To avoid overwhelming health systems, predictions for the
number of new COVID-19 cases need to be considered when choosing a school
reopening strategy. Using computer simulation, we analyze different strategies
to reopen schools in the Sao Paulo Metropolitan Area, including the official
reopening plan. Our results indicate that reopening schools with all students
at once has a big impact on the number of new COVID-19 cases, which could cause
a collapse of the health system. On the other hand, a controlled school
reopening avoids the collapse of the health system, with a maximum ICU
occupancy between 48.8% and 97.8%, depending on how people attending school
follow sanitary measures. Postponing the schools' return date for after a
vaccine becomes available can save up to 37,753 lives just in the Sao Paulo
Metropolitan Area.
