Can Schools Open Safely

March 30, 2021


A new CDC study makes the argument for keeping children in school for in-person learning during the COVID-19 pandemic (with certain caveats).

Here’s what it says:

New Study: The Basics

  • What: 17 schools participated in a study examining in-school transmission of COVID-19 over the course of 13 weeks.
  • Where: A rural Wisconsin county.
  • When: Late August to late November.
  • Who: 4,876 students and 654 staff members. 8 elementary schools (K-6); 9 secondary schools (grades 7-12).
  • Public and private school districts, including 1 independent school.

Parameters for Participants

  • Each student received 3-5 masks with 2-3 layers (funded by grant money) and wore masks in school; there were district and statewide mask mandates in place at the time.
  • Students stayed in cohorts of 11-20 students; if possible, students consistently sat next to the same person.
  • Social distancing recommended.
  • All classes and lunch held indoors.

The Rules

If a student tested positive and quarantined, their siblings *also* automatically quarantined (length of quarantine not specified in study).

If a student/staff tested positive, anyone with close contact (sitting within 6 feet for 15 minutes or more) automatically quarantined.

What Happened?

  • 133 students and 58 staff members tested positive for COVID-19.
  • 3.7% of cases (7 cases – all students) were tied to in-school transmission.
  • No known child-to-staff member transmission.
  • Context: Researchers say despite “widespread community transmission” in the county overall, these schools had a 37% lower infection rate than the surrounding community.

Bottom Line

“These findings suggest that, with proper mitigation strategies, K–12 schools might be capable of opening for in-person learning with minimal in-school transmission of SARS-CoV-2.”

The CDC research team notes mitigation and masking efforts, and acknowledges the study has demographic, regional and technical limitations.

Something to Consider

  • An estimated 56+ million Americans are in school K-12.
  • About half of American schooling remains virtual (as of the study date).
  • Just over half of teachers in this study participated in the weekly surveys (on mask compliance, class attendance), which limits some of the data.
  • Researchers did not proactively test students and staff for COVID-19 to identify any asymptomatic cases.

Are kids safer in school? The study stops short of saying definitely, using the word “might” 14 times. Additional limitations to the study: Participants were mostly non-Hispanic white in a rural, middle-to-low income area. Available data showed mask compliance was over 90% regardless of grade; school ventilation systems were not studied.

COVID-19 Cases and Transmission in 17 K–12 Schools — Wood County, Wisconsin, August 31–November 29, 2020

by Jenna Lee,