WHO says it’s keeping close eye on Delta subvariant

GENEVA — The WHO says it’s closely tracking a Delta subvariant to determine whether it is more transmissible than the original strain, as COVID-19 cases rise globally again.

It is also examining whether people are more resistant to the particular subvariant, called AY.4.2, which has been detected in at least 42 countries.

“An increase in AY.4.2 sequence submissions has been observed since July,” the World Health Organization says in its weekly epidemiological update.

“Epidemiological and laboratory studies are ongoing” to see if there was a change in transmissibility of the variant, or a decrease in the ability of human antibodies to block the virus, says the WHO.

The lineage has three additional mutations compared to the original Delta variant, including two in the spike protein — the part of the virus which latches on to human cells.

Some 93 percent of all detected cases of the subvariant were in Britain, according to data uploaded to the GISAID global science initiative.

The lineage accounted for an estimated 5.9 percent of all Delta cases reported in Britain in the week beginning October 3.