COVID second wave: Mutant variants driving rise in high-burden states On the strains, such as the double and triple mutant detected in India, they said all are the same variant of the virus, and the available vaccines are effective on them. Share Via Email | A+A A- A healthcare worker prepares to collect a swab sample from a passenger at the Kempegowda Bus Station in Bengaluru on Sunday. (Photo | Shriram BN/EPS) By Express News Service NEW DELHI: Experts engaged in genome analysis say that one of the reasons behind the surge in the Covid-19 cases could be increasing mutant variants in many cities, especially in high-burden states.