WHO Closely Monitoring New Variant BA.2.86

#17,621

For the past couple of days virologists around the globe have been examining three similar COVID sequences (2 from Denmark, 1 from Israel) recently deposited at GISAID that carry > 30 mutations in their spike protein.  

At this point, there isn't enough information to even begin to quantify the risk. We don't know how well it transmits, or how stable it is, or whether it is more - or less - dangerous to humans. 

But there is a lot of interest because 20 months ago, we saw a similar report from South Africa (see NICD Statement On B.1.1.529 Variant) on a variant which also carried an unusual number of mutations. That turned out to be the start of the Omicron lineage of COVID, which while milder than Delta, was far more transmissible. 

This new variant has been dubbed BA.2.86, and it appears to be a descendant from the BA.2 variant which peaked in the United States over a year ago, and as of the last CDC Nowcast, was estimated at between 0.0% and 0.1% of US cases. 

Yesterday Denmark's SSI posted on Twitter/X:

Today they followed up with: 

Today the WHO officially added BA.2.86 to their list of Currently circulating variants under monitoring (VUMs) (as of 17 August 2023)

Whether BA.2.86 turns out to be a brief flash in the pan, or the start of a new phase of COVID, remains to be seen.  A large number of mutations in the spike protein is concerning, but it could just as easily undermine the virus's `fitness'.

Time will tell.

In the meantime, EG.5 is on the upswing globally, and in the United States, and regardless of the trajectory of BA.2.86, we will have to deal with that in the near term.