04 March 2021
The new SARS-CoV-2 variant B.1.1.7 detected in the UK is rapidly spreading to other European countries. Due to concerns about these variants and high incidence levels, progressively enhanced social distancing measures were introduced in France in 2021. A curfew was imposed throughout the country and new recommendations on teleworking and the use of preventive measures were made with these measures being tightened later in January. However, the presence of the B.1.1.7 variant poses a critical additional challenge to combating the epidemic. Social distancing will have a different effect on this variant and the historical strain.
Using a 2-strain mathematical model calibrated on genomic surveillance, RECOVER scientists estimated that social distancing allowed hospitalizations to plateau, by decreasing transmission of the historical strain while B.1.1.7 continued to grow. The dominance of the B.1.1.7 variant is expected in late February/early March in France, with great geographical heterogeneity. Without reinforced social distancing, a rapid increase in hospital admissions is expected in the coming weeks. Strengthening social distancing measures offers clear advantages in gaining time to extend the plateau before the expected resurgence of cases. In the absence of stronger and more intensive social distancing, B.1.1.7 will grow rapidly in the coming weeks. Increasing vaccination coverage is essential, but its mitigating effect is expected to be visible from April onwards, according to the estimated roll-out plans and assuming that vaccination is only effective against symptomatic forms of infection.
Read the preprint article here.
Authors: Laura Di Domenico, Chiara E. Sabbatini, Giulia Pullano, Daniel Lévy-Bruhl, Vittoria Colizza