Drs. Pascal Lavoie and Louise Mâsse from the University of British Columbia and their team have released new findings from their CITF-funded study of SARS-CoV-2 transmission in Vancouver schools. In a pre-print, not-yet peer reviewed, their results suggest that despite the presence of variants of concern last spring, there was low transmission of SARS-CoV-2 in schools from kindergarten to grade 12, where appropriate disease prevention measures were in place.

Key findings:

  • During the study period (April to June 2021), 69 cases of COVID-19 were identified among K-12 students and staff.
  • Of positive cases, 65 (94%) were among students and four (6.2%) among staff.
  • Of 229 individuals identified as being in close contact with the infected person at school, 3 tested positive (1.3%), of whom 2 were detected through asymptomatic testing.
  • Most transmission (90%) occurred in households.

The researchers observed a low proportion of teachers or students getting SARS-CoV-2 in the school setting, even when accounting for asymptomatic cases. Depending on such factors as local testing rates, the preventive measures that are in place, and associated costs, asymptomatic testing may prove to be a useful part of a broad detection strategy, particularly as rapid antigen tests become more accessible.

Choi A, Mâsse L.C., Bardwell S, Zhao Y, Xu YXZ, Markarian A, Coombs D, Watts A, Macdonald A, Dhillon N, Irvine M O’Reilly C, Lavoie PM, Goldfarb D. Symptomatic and asymptomatic transmission of SARS-CoV-2 in K-12 schools, British Columbia, April to June 2021. medRxiv. 2021 Nov 20. doi.org/10.1101/2021.11.15.21266284