Lineage B.1.617 is a lineage of SARS-CoV-2, the virus that causes COVID-19.[1] It first came to international attention in late March 2021 after the newly established INSACOG performed genome sequencing on positive samples throughout various Indian states. Analysis of samples from Maharashtra had revealed that compared to December 2020, there was an increase in the fraction of samples with the E484Q and L452R mutations.[2] Lineage B.1.617 later came to be dubbed a double mutant by news media.[3]
Lineage B.1.617 has three sublineages according to the PANGO nomenclature: