Because of its rapid transmission not just in India but in several other countries, the WHO graduated it from a "variant of interest" (VOI) to a "variant of concern" (VOC)
According to Indian scientists, the Delta variant is responsible for the severe second wave in India. First identified in Maharashtra, it was previously labelled as B.1.617.2.
Because of its rapid transmission not just in India but in several other countries, the WHO graduated it from a “variant of interest” (VOI) to a “variant of concern” (VOC).
But, what sets the Delta variant apart from other strains?
 "What is Delta variant of Covid and how effective are vaccines against it?")
