COVID-19 evolution: AY.4.2 Delta variant on the rise in UK

A COVID-19 variant, AY.4.2, was recognized earlier in the year in the UK, but is now gaining attention because of its surge there, according to the UK Health Security Agency.

AY.4.2, which some are calling "Delta plus," contains mutations that might give the virus survival advantages. In addition to its rise in the UK, the Delta subvariant has been found around the world in 27 countries.

“UK reported its biggest one-day Covid case increase in 3 months just as the new Delta variant AY.4 with the S:Y145H mutation in the spike reaches 8% of UK sequenced cases,” Scott Gottlieb, MD, former FDA commissioner, said in an Oct. 17 tweet. “We need urgent research to figure out if this Delta plus is more transmissible, or has partial immune evasion.”

The Delta variant still predominates in the US and UK, but the U.S. Centers for Disease Control and Prevention (CDC) mentions the AY variants as a concern, and suggested that it may be more contagious and more severe than the original COVID-19 strain.

As of now, not a great deal is known about this variant and its danger to the public. However, it is clear that it is slowly gaining a grip in the UK.

Gottlieb urged that investigators quickly characterize this variant and others as they pop up.

According to Newsweek, the variant is not currently listed as a distinct variant of concern or a variant of interest by the U.K., World Health Organization, or the CDC.

Francois Balloux, director at the University College London Genetics Institute, said on Twitter on Saturday that data about AY.4.2 suggested it could be 10 percent more transmissible than the most common Delta variant in the UK, called AY.4.

"As such, it feels worthwhile keeping an eye on it," he said.