We have published a new paper in The Lancet Infectious Diseases on strategies to minimize school closures during the COVID-19 pandemic. This study uses high-resolution SocioPatterns contact data from primary and secondary schools, combined with data from pilot screenings in 683 schools during the alpha variant wave in France, to evaluate the costs and benefits of different intervention protocols.
Using an agent-based model of SARS-CoV-2 transmission, we estimated school-specific effective reproductive numbers for the alpha and delta variants. The results show that weekly testing of 75% of unvaccinated students (PCR tests on saliva samples in primary schools and lateral flow tests in secondary schools), in addition to symptom-based testing, would reduce cases by approximately 35% compared with symptom-based testing alone. Regular testing would also reduce student-days lost by up to 80% compared with reactive class closures.
The findings indicate that extending vaccination coverage in students, complemented by regular testing with good adherence, are essential steps to keep schools open when highly transmissible variants are circulating. Even with moderate vaccination coverage in students, regular testing provides additional control benefits.