XBB.1.5 'Kraken' Omicron Subvariant Drives New U.S. Wave

The XBB.1.5 Omicron subvariant — nicknamed 'Kraken' by some scientists — becomes dominant in the U.S. by January 2023, demonstrating enhanced immune escape capabilities. WHO designates it the most transmissible Omicron subvariant detected to date. It drives renewed winter waves in the U.S. and Europe.