'Marginally more infectious': New mutation of COVID-19 Delta variant being monitored in England

The development comes as Downing Street said that it is keeping a "very close eye" on the rising number of daily coronavirus cases in the UK, which hit 49,156 on Monday.

London: A new mutation of the Delta variant of COVID-19 is expanding in England and is being monitored and assessed, according to official UK health data reported on Tuesday.

AY.4.2, which is being dubbed as "Delta Plus" in some quarters, contains mutations that might give the coronavirus which causes COVID-19 a greater survival advantage.

The "sublineage" is increasing in frequency but experts do not believe it is responsible for the continued high number of daily coronavirus infections in the country, which hit 49,156 cases on Monday, the highest figure since July.