A previous post highlighted efforts to track COVID-19 cases connected to K-12 schools, and now more evidence is available on the role of in-person schooling in community spread. Much of the new research suggests that students in schools are not contributing to COVID-19 transmission above and beyond what is already happening outside of school building walls, but there are some important caveats when considering this evidence in school reopening/closing decisions.
Schools Have Not Sped the Spread
As school administrators and local leaders made decisions about returning in person this fall, there was concern that reopening school buildings could lead to COVID-19 outbreaks among students and staff, contributing to community spread in turn. Emily Oster, a Brown University economist leading the efforts behind the COVID-19 School Response Dashboard, which tracks confirmed cases among students and staff in schools across the country, reported early findings from the data thus far in an article published this week in The Atlantic. Oster notes that COVID-19 case rates for in-person schools have typically been low since opening (i.e., “well under half a percent,” even in high-risk areas) and are similar to case rates in the broader community. This finding highlights the influence of community transmission on schools, rather than the reverse. This work provides additional data in the school reopening debate (an article in the New England Journal of Medicine summarizes these arguments), and Oster encourages leaders to consider this evidence when weighing the risks of virus spread in school against the risks to student well-being and academic progress from remote learning. It is important to note that the dataset is limited to participating schools and the coverage is not necessarily representative of schools and districts across the country.
Evidence from Outside the U.S.
A recent working paper uses an event study design that capitalizes on variation in school location and time of reopening to assess the impact of returning to in-person instruction on COVID-19 transmission in Germany. The authors find no evidence that school reopenings caused an increase in case numbers. Importantly, they note that these results might not translate to other contexts—school reopenings in Germany were under strict hygiene, quarantine, and containment protocols, and occurred at a time when community spread in Germany was relatively low. Moreover, the researchers have only looked thus far at the three-week window after a school reopening, so caution is appropriate when considering the longer-term ramifications as well as other contexts for school reopening decisions.
Evidence from Childcare Centers
Another recent study examines the impact of in-person childcare on infection outcomes for providers. The authors focus on the first three months of the pandemic in the U.S., with data from over 57,000 child care providers. Results suggest—as with the findings for schools—that in-person childcare was not associated with higher incidence of COVID-19 cases. Like the study of school reopenings in Germany, the authors emphasize the importance of context: child care providers covered by this study reported high rates of practicing a variety of infection mitigation strategies (e.g., small group sizes, frequent hand-washing, daily disinfection of surfaces, symptom screening, and social distancing measures). This study also points to community transmission being the driver of infection in childcare settings; the authors note that while childcare may do little to influence community transmission, community infection rates may affect COVID-19 cases within childcare settings and threaten centers’ ability to remain open.