Detecting Rapid Spread of SARS-CoV-2 Variants, France, January 26–February 16, 2021

S ince the end of 2020, at least 3 strains, or "vari- ants," of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) bearing a high number of mutations have been associated with rapid epidemic spread in the United Kingdom (lineage B.1.1.7)(1), South Africa (lineage B.1.351)(2), and Brazil (lineage P.1) (3).Because of their increased transmissibility (4; E. Volz et al., unpub.data, https://www.medrx-iv.org/content/10.1101/2020.12.30.20249034v2;A.S. Walker et al., unpub.data, https://www.medrxiv.org/content/10.1101/2021.01.13.21249721v1) and potential ability to evade host immunity (5; S. Cele et al., unpub.data, https://www.medrxiv.org/content/10.1101/2021.01.26.21250224v1), monitoring these variants is crucial in the context of mass vaccination.In France, beginning February 5, 2021, every sample that tested SARS-CoV-2-positive by reverse transcription PCR (RT-PCR) underwent an additional variant-specifi c RT-PCR with probes targeting the Δ69-70 deletion and the N501Y mutation, both in the spike glycoprotein.Both targets are present in lineage B.1.1.7.For lineages B.1.351and P.1, only the N501Y mutation is present.If only the Δ69-70 deletion is detected, the infection might be caused by another variant or by a wild-type strain with a deletion.Finally, if neither target is detected, the infection is considered to be caused by a wild-type strain.These tests are cheaper and easier to implement than full-genome sequencing, which enables their rapid deployment on a wide scale.We report the results of this testing program. Detecting Rapid Spread of SARS-CoV-2 Variants, France,