http://www.newsweek.com/delta-plus-ay-4-2-sub-variant-seven-states-more-infectious-delta-1640359

A new mutated version of the COVID Delta variant spreading in the U.K. could be 10 percent more transmissible than Delta, researchers think.

However, it's too early to say whether this strain could be more evasive to immunity than Delta and it also doesn't appear to be taking over as fast as Delta did from Alpha.