The XBB.1.5 variant is on a growth spurt in USA
As everyone who has been following the Omicron family of SARS-CoV-2 descendants in recent months, there’s a swarm of new subvariants. One of these is XBB, which is a recombinant (fusion) of 2 different BA.2 variants, BJ.1 (BA.2.10.1.1) and BA.2.75 (BA.2.75.3.1.1.1), depicted below by both the tree and mutation map. Phylogenetic tree with scale bar indicating genetic distance, from Wang et al , Cell Mutation map by Tom Peacock Dr. Emma Hodcroft also has a terrific diagram to show the recombination between 2 variants that resulted in XBB Now it appears that in New York State, XBB evolved further to XBB.1.5, with new mutations, which was aptly first noted by JP Weiland a couple of weeks ago, coincident with the beginning of a steep rise of hospitalizations there. The key mutation of XBB.1.5 is clearly F486P, which had been identified many months ago by the Bloom lab as one that would be tied to