USA: BA.2.12.1 has transmission advantage of ~25% over BA.2 – *1 UPDATE*

BA.2.12.1, BA.4, BA.5, Coronavirus, Genome, Infection, New York State, North Carolina, Testing, USA

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.”

CDC: Transcript for CDC Media Telebriefing: Update on COVID-19, 26th April 2022

 

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 using Raj Rajnarayanan’s Covid lineage tracker:

 

 

BA.2.12.1 is showing up strongly in New York and North Carolina at the moment:

 

Raj Rajnarayanan’s Covid lineage tracker

 

For Nextstrain purposes, BA.2.12.1 is designated 22C:

 

This Trevor Bedford thread outlines why BA.2.12.1, BA.4 and BA.5 could present a problem going forward:

 

 

UPDATE 1 – 3rd May 2022

BA.2.12.1 now at 36% of samples according to CDC:

 

 

 

 

Image by Gerd Altmann from Pixabay

** This post was originally published on May 2, 2022 **