The WHO said on Tuesday that only one strain of the Covid-19 Delta variant first detected in India was now considered "of concern", while two other strains had been downgraded.
The B.1.617 variant of the virus, which has been blamed for the explosive outbreak in the country, has been dubbed a triple mutant variant since it is split into three lineages.
The UN health agency had last month declared the entire strain a "variant of concern", but on Tuesday, it said only one of the sub-lineages deserved that label.
The B.1.617.2 variant, now named Delta, remains a "variant of concern", the WHO said, adding that B.1.617.1 variant, now named Kappa, is a "variant of interest".