Early assessment of diffusion and possible expansion of SARS-CoV-2 Lineage 20I/501Y.V1 (B.1.1.7, variant of concern 202012/01) in France, January to March 2021

Abstract

The emergence of SARS-CoV-2 variant 20I/501Y.V1 (VOC-202012/1 or GR/501Y.V1) is concerning given its increased transmissibility. We reanalysed 11,916 PCR-positive tests (41% of all positive tests) performed on 7–8 January 2021 in France. The prevalence of 20I/501Y.V1 was 3.3% among positive tests nationwide and 6.9% in the Paris region. Analysing the recent rise in the prevalence of 20I/501Y.V1, we estimate that, in the French context, 20I/501Y.V1 is 52–69% more transmissible than the previously circulating lineages, depending on modelling assumptions.

The SARS-CoV-2 B.1.351 lineage (VOC β) is outgrowing the B.1.1.7 lineage (VOC α) in some French regions in April 2021

“…Since January 2021, the national guideline is to test all clinical samples that are positive for SARS-CoV-2 with an additional reverse-transcription (RT)-PCR to detect mutations indicative of certain variants [7,8] We used the ID SARS-CoV-2/N501Y/E484K Quadruplex assay (ID Solution, Grabels, France) to test 53,687 SARS-CoV-2 positive samples collected between 12 April and 7 May 2021 in 13 French regions, with the majority of samples coming from the Île-de-France region (Table 1). Some of the total samples (7-8%, Table 1) originated from hospitals (mostly hospitalised patients), the rest from the general population.…”

Lockdown as a last resort option in case of COVID-19 epidemic rebound: a modelling study

“…Even if epidemic growth is initially slow, it may accelerate over time and become less manageable for example because of a saturation of resources for testing and contact tracing, increased risk of superspreading events, changing climate conditions [ 11 ] or spatial expansion. An increase in the frequency of more transmissible variants [ 14 , 15 ] could also result in an acceleration of the epidemic. For all these reasons, it is important to respond robustly and promptly to any rebound, even those that start slowly.…”

Impact of January 2021 curfew measures on SARS-CoV-2 B.1.1.7 circulation in France

“…The new B.1.1.7 variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (20I/501Y.V1, also called variant of concern (VOC) 202012/01) initially detected in the United Kingdom [1,2] has rapidly expanded its geographical range across European countries [3]. A large-scale genome sequencing initiative was conducted in France on 7-8 January (Flash1 survey [4], the first of a set of surveys), reporting that 3.3% of all SARS-CoV-2 detections were B.1.1.7 viruses. To limit SARS-CoV-2 spread, strengthened social distancing measures were implemented in the country in the month of January.…”

“…The presence of the B.1.1.7 variant on the territory, however, poses critical challenges to epidemic control. Its higher transmissibility represents a strong selective advantage that makes it prone to rapidly becoming the dominant strain [1,2,[4][5][6][7][8]. Social distancing has a differential impact on the variant and the historical strains, not visible before the implementation of surveillance that monitored variant frequency over time.…”