XBB.1.5 at a staggering FORTY PERCENT of sequences in the US

Coronavirus, Genome, Infection, New York State, Recombination, Reinfection, Research, Testing, Transmission, USA, XBB.1.5

These numbers were so shocking that, when they were leaked online yesterday, we didn’t believe them.

From literally nowhere, XBB.1.5, aka the Kraken variant, has leapt to 40% of sequences on the US CDC’s weekly-updated variant tracker page. Last week, it wasn’t even listed as a variant.

We knew that XBB.1.5 was big in New York, but the variant must have swept across the US like a hurricane in the last couple of weeks to achieve its current status as the dominant variant in the country.

When the variant tracker numbers were leaked online yesterday, prior to their official release, they were so bad we actually didn’t believe them.

Why are these figures so stunningly bad? For the simple reason that if you take a hyper-transmissable variant like XBB.1.5 and add a Delta variant like lethality to it, the country, or indeed the entire planet, could be facing an unprecedented and potentially irreversible disaster. 

The latest CDC variant numbers were leaked online by Eric Feigl-Ding hours before the official release. Quite clearly, at least one person at the CDC is worried about these developments:


Raj Rajnarayanan has already put up some charts showing where XBB.1.5 hotspots in the US are, and how XBB.1.5 penetration in US compares to other countries. XBB.1.5 is currently growing fastest in New York and the southern and eastern states of the US.


This graph compares XBB.1.5 penetration in the US compared to other countries:


Finally, giving some granular location information to the XBB.1.5 outbreak, this list shows where the most cases have been sequenced across the globe, wIth New York right at the top of the list.


Back to Eric Feigl-Ding for a final word:


You were probably hoping for more, but this is what the CDC has to say about XBB.1.5:

CDC advice on XBB.1.5


More from Eric Feigl-Ding




XBB.1.5 growth rate in England:



Walgreens US Covid-19 positivity tracker exceeds 40% for the first time ever:



You can view all of Raj Rajnarayanan’s Covid-19 visualizations at this link

Raj Rajnarayanan’s Twitter account is here


XBB.1.5 has a much higher hACE2 binding affinity than XBB.1



** This post was originally published on December 30, 2022 **