No model can predict what will happen in a single school. The infection rates vary from district to district. Luck does matter. And the effectiveness of measures like mask-wearing and social distancing depends on the dynamics at each school, how compliant students are, and what activities are restricted.
The reopening of the school has become a tangled logistical process around the world as officials, administrators, teachers, parents and students have had to discuss measures such as face protection, ventilation, shift learning and the partial or full virtual implementation. Most of the country’s major school districts, with the exception of New York City, have gone completely virtual for most or all of the fall semester as educators, their unions, and some parents have persistently high virus rates and concerns.
The reopening has been particularly difficult in New York, where Mr de Blasio delayed the start of face-to-face tuition twice due to a staff crisis and the backlash from the unions representing the city’s teachers and principals.
School systems around the world have had very different results when they reopened. Some countries, like Israel, have experienced explosive outbreaks despite containment measures. Others, like Ireland and South Korea, have opened schools without any major problems.
To simplify their modeling, the NYU team chose a benchmark for New York: Germany, which it claims has largely similar background infection rates, mitigation efforts, and levels of virtual teaching.
Alex Perkins, an infectious disease epidemiologist at Notre Dame who reviewed the analysis, said it made sense to use Germany as a benchmark and “what the model says about more frequent testing is moving in the right direction,” he added : “But I think there is more room to refine the model based on the transfer rates we actually see in New York schools.”
The city is razor sharp, said the NYU researchers. Classes could continue with rigorous tests and other measures, but it would be impossible to avoid flare-ups entirely.