CDC: “BA.2.12.1 might have a transmission advantage of about 25% over the BA.2 sub variant… The BA.2.12.1 sub variant makes up nearly 30% of sequences identified nationally.”
CDC Director Rochelle Walensky: “Right now, BA.1 is only about 3% of the sequences identified. We are now more commonly finding the BA.2 Omicron sub variant, which makes up about 68% of circulating virus. More recently, we’re finding the BA.2.12.1 sub variant, which was first identified in upstate New York, and which makes up nearly 30% of sequences identified nationally. We are just starting to learn about the impact of BA 2.12.1.”
“It appears [BA.2.12.1] might have a transmission advantage of about 25% over the BA.2 sub variant. Additional evaluation is currently underway to understand the impact of BA.2.12.1 on vaccine effectiveness.”
Although BA.2.12.1 has a strong showing in certain areas of the US, it looks like it may be losing some momentum nationally compared to BA.2.9 usingRaj Rajnarayanan’s Covid lineage tracker:
BA.2.12.1 is showing up strongly in New York and North Carolina at the moment:
For Nextstrain purposes, BA.2.12.1 is designated 22C:
22C is primarily circulating in the Northeast of the US. Its recent expansion can be seen at https://t.co/j0AeWV3ouG. Thanks to @CDCgov and a large number of academic groups who’ve contributed to genomic surveillance in the US. 4/6 pic.twitter.com/YJwvbeMbjD
This Trevor Bedford thread outlines why BA.2.12.1, BA.4 and BA.5 could present a problem going forward:
We're now starting to see the evolution of new potentially impactful sublineages of Omicron with particular focus on mutations at spike residue 452. Here, I'd like to highlight lineages B.2.12.1 in New York, as well as BA.4 and BA.5 in South Africa. 1/17
New York is now a hot spot for rising #COVID19 cases from a variant called BA.2.12.1. The state is home to 37 out of the 54 U.S. counties the CDC says have high levels of community transmission. https://t.co/Ho5yNwf0CO
