Schools and Coronavirus Disease 2019 Prevention

To the Editor—The article, “Effectiveness of Three Versus Six Feet of Physical Distancing for Controlling Spread of COVID-19 Among Primary and Secondary Students and Staff: A Retrospective, State-wide Cohort Study,” by van den Berg et al in the March 2021 issue of Clinical Infectious Diseases [1] has limitations that undermine the conclusions, thereby calling into question policies developed as a result of this study.

The methods included only “eligible” Massachusetts schools with in-person instruction between 24 September 2020 and 27 January 2021, which appears to have excluded Boston, Brockton, Chelsea, Framingham, Holyoke, Lawrence, Lowell, Lynn, Springfield, and Worcester, with remote-only instruction [2]. These cities had some of the highest rates of Massachusetts coronavirus disease 2019 (COVID-19). One result is the underrepresentation of Black and Hispanic students in the study compared with Massachusetts student enrollment (6.97% vs 9.3%, 15.99% vs 22.3%) [3]. It is not warranted to apply lessons from a study that excluded most urban schools to all school systems.

The methods assessed written plans but not implemented practices. No evaluation was conducted regarding actual attendance and spacing of students, building ventilation and filtration, or even adherence to masking policies. Nor was information collected about whether classrooms or schools were closed when COVID-19 clusters occurred.

The conclusions are contradicted by recent research that documented airborne spread at distances greater than 6 feet and higher rates of disease among Black and Hispanic children [4]. Modeling predicts that when schools open, 5%–24% of schools would have at least 1 person with active COVID-19, with transmission mitigated by hybrid attendance [5]. A Wales study found a 12% increase in the odds of testing positive within year groups, with pupil–pupil transmission linked to schools [6]. A meta-analysis found decreasing severe acute respiratory syndrome coronavirus 2 transmission with increasing distance, with measurable difference between 3 and 6 feet [7].

Several variants of concern are now circulating in the United States, causing outbreaks in schools and student sports teams [8], demonstrating greater transmissibility and potentially more severe health outcomes in adults and children [9]. Allowing schools to expand occupancy levels and decrease physical distancing could spell disaster for teachers, staff, students, their families, and communities in upcoming surges.

Note

Potential conflicts of interest. L. M. B. reports receiving consulting fees while on contract with the National Education Association on health and safety issues related to coronavirus disease 2019 in schools. All remaining authors: No reported conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed.