COVID-19 Delta variant mutant AY.4.2 may be more transmissible: UK health agency

The UK Health Security Agency confirmed that the Delta variant sub-lineage (Delta AY.4.2) was designated a Variant Under Investigation (VUI) on October 20, and has been given the official name VUI-21OCT-01. The UKHSA said the designation was made on the basis that this sub-lineage has become increasingly common in the country in recent months, and there is some early evidence that it may have an increased growth rate in Britain.