RESUMO
In this paper we present a method do estimate the risk of reopening schools illustrated with the case of the State of São Paulo, Brazil. The model showed that, although no death of children would result from the reopening of the schools in the three cities analyzed, the risk of asymptomatic and symptomatic cases and secondary cases among teacher, school staff and relatives of the children is not negligible. Although the epidemic hit different regions with different intensity, our model shows that, for regions where the incidence profile is similar to the cities analysed, the risk of reopening schools is still too high. This in spite of the fact that incidence in these cities were declining in the period of time considered. Therefore, although we cannot extend the result for the entire country, the overall conclusion is valid for regions with declining incidence and it is even more valid for regions where incidence is increasing. We assumed a very conservative level of infection transmissibility of children of just 10% as that of adults. In spite of this very low level of transmissibility assumed, the number of secondary cases caused by infected children among teachers, school staff a relatives varied from 2 to 85. It is therefore too soon to have any degree of confidence that reopening school before the advent of a vaccine is the right decision to take. The purpose of our model and simulations is to provide a method to estimate the risk of schools reopening, although we are sure it could be applied as a guide to public health strategies.