BA.2.86 is the latest variant to watch; send me your questions

Last week, several variant experts that I follow on Twitter (which I refuse to call by its new name, thanks) started posting about a new SARS-CoV-2 variant, first detected in Israel. They initially called it Omicron BA.X while waiting for more details to emerge about the sequence; it’s now been named BA.2.86.

Scientists and health officials are concerned about BA.2.86 because it has many mutations on its spike protein, showing significant deviation from other versions of Omicron. This variant evolved from an earlier Omicron strain (BA.2) rather than XBB, which is the primary lineage spreading across the world right now—and is the primary focus of booster development for this fall.

Here are two relevant threads with more info (the first for a more general audience, the second going into more details about mutations):

Quick summary of the "BA.X" variant that trackers are watching closely. Bear in mind, there are only a few sequences of it so far and it may not be able to compete with currently dominant variants and may not take off. But it's interesting and *potentially* concerning.

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— T. Ryan Gregory (@TRyanGregory) August 15, 2023

I wanted to provide assessment of spike amino-acid mutations in new highly mutated 2nd generation BA.2 SARS-CoV-2 variant

This is analysis for those (like me) scientifically interested in SARS2 evolution

(Anyone else is completely within reason to ignore this variant right now) https://t.co/76b5Lr7HgH

— Bloom Lab (@jbloom_lab) August 16, 2023

Virologists hypothesize that BA.2.86 may have evolved in someone with a chronic infection—essentially gaining more and more mutations as the same person stayed sick for many months. Similar hypotheses apply to Delta and Omicron, though it’s hard to get definitive answers without actually finding those patients.

Another reason for concern: as of today, BA.2.86 has been detected on three different continents. In addition to Israel, scientists have found it in Denmark and the U.S. Since most countries are not doing rigorous genomic surveillance these days, the cases found so far suggest that this variant is actually far more widespread; it just went undetected until now.

The World Health Organization recently designated BA.2.86 as a Variant Under Monitoring, meaning that its genetic information suggests concern but little else is known at this time. The CDC has also said it’s tracking the new variant.

I’m keeping today’s post about BA.2.86 short due to the limited information we have so far. But I’d like to dive into it more next week. So, send me your questions about this variant or about genomic surveillance more broadly, and I will answer them in next Sunday’s newsletter.