Study: In-class college COVID spread rare amid public health mandates

At Boston University (BU), which mandated COVID-19 vaccination and face coverings for students, faculty, and staff in fall 2021, only nine cases of SARS-CoV-2 transmission were identified among more than 140,000 full-occupancy, in-person class meetings.

None were confirmed to be the result of in-class transmission.The findings were published late last week in JAMA Network Open.Genomic sequencing used to identify linkagesIn the study, BU researchers used weekly COVID-19 surveillance test results, contact tracing, class attendance records, and whole-genome sequencing to analyze infections among all 33,000 students, who lived on or off campus, from Sep 1 to Dec 1, 2021, a period dominated by the SARS-CoV-2 Delta variant.Possible in-class viral transmission was considered after two or more positive polymerase chain reaction (PCR) COVID-19 tests from students or faculty in the same class who did not identify each other as close contacts outside the classroom.

Exposures outside the classroom included those at social gatherings, dining halls, study groups, and athletic activities.When cases of potential in-class spread were identified, the researchers assessed the genetic relationship of SARS-CoV-2 material isolated from infected students to identify those that were likely part of a linked transmission event.

The team successfully sequenced the genomes of 96.4% of samples.In a BU news release, corresponding author John Connor, PhD, explained that in linked SARS-CoV-2 transmission events, samples from the people involved have the same viral genome. “If there was not in-class transmission then the two people would have genomes that are genetically different," he said. "It turned out that none of the nine potential in-class