Thread by @sailorrooscout

Guys, BA.2 isn’t new. It’s been around since last year. It’s a sub-lineage to BA.1. They’re both still Omicron. It isn’t expected to be any more severe or expected to cause another wave. It might just eventually replace BA.1. End of the day, still Omicron. Let’s not lose focus.

Per @PeacockFlu: BA.2 shares a lot of mutations with BA.1, but it also has some differences. BA.2 also lacks the Spike Δ69-70 mutations. It means it does not cause S gene target failure. Remember the “stealth” version of Omicron? Yeah, that’s BA.2. theguardian.com/world/2021/dec…

Just so I can prove this isn’t necessarily new you can see here. BA.2 appears to be the major Omicron lineage in (part of) India and the Philippines and there is evidence it is growing compared to BA.1 in Denmark, UK, Germany and some other areas.

So why is it in the news? Due to its growth in several countries, that’s likely why you’re hearing more about it and it might be somewhat more relevant transmissible than BA.1 but we really don’t know that yet. But that’s really it. What do we know though?

As @PeacockFlu stated, and I HIGHLY recommend reading his thread: Very EARLY observations from India and Denmark suggest there is NO dramatic difference in severity compared to BA.1 and would also agree with this that there is likely to be minimal differences in vaccine

effectiveness against BA.1 and BA.2 and, it is also highly likely BA.1 infection will give decent cross-reactivity against BA.2 infection.

I’m going to link Tom’s thread here. If it isn’t showing up let me know. Twitter can be funny about QRTs sometimes.

https://twitter.com/peacockflu/status/1483768659420094464

So, in the end, those whose JOB it is to focus on sequencing and surveillance should be focused on BA.2 and other sub-lineages. I agree with Tom that I really don’t think BA.2 , is going to have a substancial impact on the current Omicron wave of the pandemic as several countries

are near, or even past the peak of BA.1 waves and would be very surprised if BA.2 caused a second wave at this point. As Tom says: Even with slightly higher transmissibility this absolutely is not a Delta -> Omicron change and instead is likely to be slower and more subtle.

Could BA.2 eventually replace BA.1? Absolutely. Variants will do what they do. However, at the end of the day, this is STILL OMICRON. Remember “Delta Plus?” Yeah, that was all still Delta at the end of the day. Make sure you’re protected. Stay vigilant. Stay calm. This isn’t new.

Out of Denmark: Initial analysis shows NO differences in hospitalizations for BA.2 compared to BA.1. en.ssi.dk/news/news/2022…
H/T: @v_margar

Per Tom: BA.2 is antigenically similar but more transmissible its likely to exacerbate existing Omicron waves- think enhanced/drawn out peaks (such as what we are seeing in Denmark), and delays or even transient reversal of decreases- what it wont do is immediately cause a second

equal Omicron wave. For those who are saying France and Denmark are in “another” wave or resurgence. That is incorrect. This IS still their Omicron wave. They didn’t get out of their first wave and then have a reinfection surge with BA.2. BA.2 IS their Omicron wave.