The Kappa variant is one of the three sublineages of lineage B.1.617. It is also known as lineage B.1.617.1, 21B or 21A/S:154K, and was first detected in India in December 2020. By the end of March 2021, Kappa accounted for more than half of the sequences being submitted from India. On 1 April 2021, it was designated a variant under investigation (VUI-21APR-01) by Public Health England. It has the notable mutations L452R, E484Q, P681R.