The UK Health Security Agency on Friday said it designated a Delta coronavirus subvariant called AY.4.2 as a "Variant Under Investigation", saying there was some evidence that it could be more transmissible than Delta.
"The designation was made on the basis that this sub-lineage has become increasingly common in the UK in recent months, and there is some early evidence that it may have an increased growth rate in the UK compared to Delta," UKHSA said.
"While evidence is still emerging, so far it does not appear this variant causes more severe disease or renders the vaccines currently deployed any less effective."