United States: Updated CDC Guidance Around Reopening Schools Answers Some Questions While Uncertainties Remain

On February 12, the U.S. Centers for Disease Control and Prevention (CDC) released highly anticipated guidelines for school reopening during the pandemic. Whereas administrators, teachers and parents were hoping for very specific, end-to-end guidance around school operations, the recommendations were partially successful but left significant gaps in other areas. Importantly, the report notes that these recommendations reflect the state of understanding around COVID-19 transmission in schools at this time, while acknowledging that recommendations may change as more becomes known.

Critical updates and recommendations in the CDC's guidance include:

Recommendation #1: The use of "consistent implementation of layered mitigation strategies to reduce transmission of SARS-CoV-2 in schools."

Leaning on five key mitigation strategies, the guidance recommends:

• Universal and correct use of masks.
• Physical distancing.
• Handwashing and respiratory etiquette.
• Cleaning and maintaining healthy facilities.
• Contact tracing in combination with isolation and quarantine, in collaboration with the health department.

Perhaps most consequentially, the guidance around masks recommends continuing usage of masks at all levels of community spread by all students, teachers and staff at all times, without clarifying the conditions under which mask usage may stop. Second, the guidance also continues to heavily emphasize that six feet of distance between persons is recommended, but offers some recommendations including the use of barrier screens when that distance is not feasible. Notably, the guidance does not give recommendations about how to proceed when all measures are not maximally enforced or how to dial up/down these actions based on community spread.

Recommendation #2: Indicators of Transmission

The guidelines recommend the use of two primary community transmission indicators to determine how schools should be opened. Based on: (a) the total number of new cases per 100,000 persons in the past seven days; and (b) the percentage of nucleic acid amplification (NAATs) that are positive in the preceding seven days, a community can be categorized across one of four colors - click here¹to view CDC Indicators and Thresholds for Community Transmission of COVID-19.

These changes represent a significant simplification from prior tools used to assess community risk by removing figures around infectivity (the R₀calculation), contact tracing capability and health system utilization. In areas where a community may span two separate colors, the guidelines recommend using the higher risk category.

Recommendation #3: Phased mitigation, learning modes, and testing

The guidelines recommend diagnostic testing for all students, teachers and staff who develop symptoms or have an exposure to a confirmed COVID-19 positive case. They then split schools into two groups based on asymptomatic screening testing: those that implement screening testing and those that do not. Unfortunately, the guidelines only note that some schools "may choose" to implement screening testing, but they do not offer a requirement or recommendation for when to do so. They also leave considerable latitude when it comes to recommending particular types of tests and note that antigen-based testing "may" require confirmatory polymerase chain reaction (PCR) based testing, but do not necessarily make it a requirement.

For schools that do not implement testing, the guidelines offer specific recommendations across each of the four categories for when schools should be fully in-person, hybrid or virtual. They also offer recommendations regarding sports and extracurricular activities but do not differentiate between athletics and musical/theatre activities.

For schools that do choose to offer screening testing, the guidelines recognize the higher risk of serious illness to older persons and recommend routine screening of teachers and staff once per week. Routine screening of students is not recommended in the blue level, while routing testing once per week may be offered in the yellow, orange or red categories.

Recommendation #4: Vaccinations for Teachers and Staff

Importantly, the guidelines note that teachers should be categorized as "frontline essential workers" and eligible for vaccination in Phase 1B, following health care personnel and residents of long-term care facilities. This would give teachers significant priority to receiving vaccination early, but the guidelines further note that "access to vaccination should be not considered a condition for reopening schools for in-person instruction."

Recognizing that there have been few, isolated large outbreaks in schools, the guidelines note that most school-based cases have been small incidents with little transmission occurring in schools. Provided that all of the mitigation measures are in place, the guidelines recommend opening schools without complete vaccination as a prerequisite for opening.

What's Missing?

Importantly, these updated guidelines give little guidance about school transportation and what measures need to be in place to use buses safely. They also do not address after-school care specifically and whether adjustments need to be made as children from different classes or cohorts may mix in those settings. Finally, as noted previously, the guidelines do not provide recommendations about how to scale some of these recommendations or how to adjust measures based on changing conditions in real time.

These guidelines do provide some information about which protective measures need to remain in place, the use of community transmission indicators as a means to determine what format school operations should take and what role vaccinations should play in reopening. However, the recommendations around testing, transportation and some extracurricular/after-school activities are nonspecific and will remain difficult to implement in a coordinated manner. 

Footnote

1 Tables 1 -3 sourced from CDC's Operational Strategy for K-12 Schools through Phased Mitigation.