A CDC MMWR released last week found that mitigation measures like masks and distancing were quite effective at slowing the spread of COVID-19 in schools. A new MMWR entitled Mask Use and Ventilation Improvements to Reduce COVID-19 Incidence in Elementary Schools found that rates of COVID-19 were 37% lower in elementary schools that required teachers and staff to use masks, and 39% lower in schools that took steps to improve ventilation.

In schools that improved ventilation alone (e.g. open windows, fans), COVID-19 incidence was 35% lower. Schools that combined opening windows with filtration had a 48% reduction.

Another article in the journal Science entitled Household COVID-19 risk and in-person schooling found even more striking results.

Researchers found that school-based mitigation measures (when done properly and in tandem) reduce the spread of COVID-19 so much that it is statistically the same as going to distance learning. Here’s an excerpt from the article:

School-based mitigation measures are associated with significant reductions in risk, particularly daily symptoms screens, teacher masking, and closure of extracurricular activities. A positive association between in-person schooling and COVID-19 outcomes persists at low levels of mitigationbut when seven or more mitigation measures are reported, a significant relationship is no longer observed.

Teachers working in schools had an increased risk of COVID-19, but in schools implementing effective interventions, the risk was similar to that in other in-person occupations (e.g., health care or office work). Although in-person schooling was associated with household COVID-19 risk, the risk can likely be controlled with properly implemented school-based mitigation measures.

The most important school interventions were daily symptom checks, teacher masking, and closure of extracurricular activities.

This and future research regarding the effectiveness of school-based mitigation measures provides valuable information for school districts and parents this fall, especially for grades K-5 (right now the Pfizer vaccine is only authorized for kids 12 years old and up). The evidence in these articles suggest that implementing and adhering to targeted interventions can allow schools to safely stay in-person.