New mutation of delta virus being monitored in London

According to official UK health data released on Tuesday, a new mutation of the Delta variant of Covid-19 is spreading in England and is being monitored and assessed.

AY.4.2, dubbed “Delta Plus” in some circles, contains mutations that may give the coronavirus that causes Covid-19 a better chance of survival. The “sublineage” is becoming more common, but experts do not believe it is to blame for the country’s continued high number of daily coronavirus infections, which reached 49,156 on Monday – the highest figure since July.

“New sublineages of Delta are regularly identified and designated. One recently designated sublineage is AY.4.2,” notes the UK Health Security Agency (HSA) in its latest technical briefing document.

“A Delta sublineage newly designated as AY.4.2 is noted to be expanding in England. It is now a signal in monitoring, and assessment has commenced; there are also small numbers of new cases of Delta with E484K and Delta with E484Q,” it adds.

The new mutation is not yet considered a variant of concern, or a variant under investigation – the categories assigned to variants and the level of risk associated with them. It was first noticed in July 2021 and since then this offshoot or sublineage of Delta has been slowly increasing. It includes some new mutations affecting the spike protein, which the virus uses to penetrate our cells.

“It is potentially a marginally more infectious strain,” Professor Francois Balloux, director of University College London’s Genetics Institute, told the BBC.

“It’s nothing compared with what we saw with Alpha and Delta, which were something like 50 to 60 per cent more transmissible. So we are talking about something quite subtle here and that is currently under investigation. It is likely to be up to 10 per cent more transmissible. It’s good that we are aware,” he said.