B.1.617 Covid mutation most prevalent ‘double variant’ in Karnataka: Experts The E484Q mutation has characteristics of a previously detected variant - the E484K - which was seen in the fast-spreading Brazilian and South African variants, making it highly transmissible. Share Via Email | A+A A- People queue up to buy essentials ahead of the lockdown, in Bengaluru on Sunday. (Photo | Ashishkrishna HP/EPS) Express News Service BENGALURU: The B.1.617 variant of the Covid-19, known more commonly as the double mutant strain, was first detected in India in October last year. As the name suggests, the strain involves two variants of the virus.