During Utah's pilot of the Test to Stay program in the 2020-2021 school year, about 1% of students tested positive in a typical testing event. But in fall 2021, test positivity was often closer to 5% or higher, signifying that the virus had already spread widely through the school before the event took place. According to state data, only 11 official Test to Stay events took place from August to December 2021; all are included here.