This is an extract from a recent edition of The Journal’s coronavirus newsletter, which cuts through the noise and misinformation to give you clear, accessible facts about the coronavirus, Ireland’s fight to contain it, as well as developments further afield.
This is your one-stop-shop for Covid news during a time when it can be hard or overwhelming to try and stay up to date with the latest.
You can read the full edition here, sign up to receive the newsletter here or at the bottom of the page.
IT’S THAT TIME of the Covid news cycle again when a new variant grabs the headlines.
XBB.1.5 is now the centre of attention. It has been informally given the nickname Kraken – catchy, but arguably a little unhelpful to name it after a mythical sea monster.
Viruses often evolve over time to become better at spreading and infecting people, and SARS-CoV-2 has proven to be particularly adept at this.
If it wasn’t, we’d be in a much better situation; a virus that is more stable would make immunity hold up more reliably and allow us to target vaccines significantly better.
There is a myriad of different variants out there that don’t get as much attention. You might struggle to remember BQ.1 or B.2.75, for example, and have you even heard of CH.1.1?
Some fizzle out. Some slip into circulation without much noticeable impact. Some cause a wave of infection, which happened five times in 2022 alone (January, March, July, October, and December).
Rarely do they cause the seismic impact that the arrivals of Alpha, Delta, and Omicron BA.1 – and, of course, the Wuhan variant – did.
XBB.1.5 isn’t classed among the big hitters just yet, but it stands out from the pack. It deserves a second look without cowering in terror at it.
XBB.1.5 is another sublineage of Omicron, alongside the likes of BA.1 (which swept the world in late 2021) and BA.2 (which caused a spring wave of infection in Ireland).
It’s quite distinct compared to the original Omicron but isn’t genetically distinct enough to be classed as a whole new variant, like Alpha or Delta.
Offshoot
As the name suggests, it is an offshoot of a previous variant known as XBB, which was a mishmash of – bear with me for another minute – two versions of BA.2. It caused a wave of infection in Singapore last year.
XBB.1.5. was first identified in the United States and the first cases have been identified in Ireland in recent weeks.
The reason why it’s of note is technical and involves another combination of letters and numbers, but we’ll keep it simple: The coronavirus uses a particular ‘door’ to enter human cells, and this variant is excellent at knocking that door down.
You’ll see this referred to as “ACE2 binding” or “higher ACE2 affinity”. ACE2 is a protein that the virus’s own spike protein binds to - I’ll leave it at that, but you can read in more detail here what that means.
XBB.1 already had a high level of immune escape, so this change ‘supercharges’ that ability for XBB.1.5.
Long-time subscribers will know the drill by now, that when a new variant comes along we ask three things: is it more contagious, does it cause more severe illness, and is it better at evading our existing immunity?
More contagious? Absolutely. Due to its unique combination of being already quite immune evasive and being better able to ‘break down the door’ to the human body, one expert from the World Health Organisation called it the most transmissible Omicrion sub-variant detected to date.
More virulent? There is not enough evidence to make a call on this yet. There are plenty of signs that it won’t cause more severe illness, and no signs that it will, but it’s also something you don’t want to take for granted.
Is it better at evading our existing immunity? Yes. Again, from WHO: “Along with BQ.1* variants, XBB* variants are the most antibody-resistant variants to date.”
Part two of the immunity question is whether vaccines protect will against it. In terms of severe illness, almost certainly yes.
The vaccines have time and time again shown that they hold up well in terms of preventing severe illness against all variants. There’s no reason at this stage to suggest that XBB.1.5 will make any difference in that regard.
Protection against infection, however, is likely to be reduced, even if you are at ‘peak’ immunity (up to date on boosters, including the latest bivalent vaccine, and have some recent infection history). Some antibody drugs won’t work against it, but antivirals like Paxlovid will.
It’s clear that this variant will have an advantage, and will likely grow to become the latest dominant variant in Ireland.
It’s a matter of the speed at which it does that. A slow replacement over time will cause less of an impact on society and healthcare, compared to a faster increase like was seen in late March and April last year.
But at this juncture, it seems unlikely to be anything beyond a ‘routine’ surge, like those in 2022 (that is not to belittle any surge, but governments across the world are willing to accept that this will be the case).
The professor of evolutionary biology who named it Kraken has this Twitter thread explaining why he doesn’t believe that will be the case, but thinks it’s wrong to ignore the variant completely due to the sustained pressure Covid is causing on our health and health systems.
It grew significantly in some parts of the United States over recent weeks, but appears to have slowed down to some extent.
Some scientists have even posited that this brief surge in the US could be down to timing: a cold snap + holiday gatherings = more transmission.
Equally, it could only be getting started – the US east coast is where we need to look in order to figure out what will happen with XBB.1.5.
This is an extract from a recent edition of The Journal’s coronavirus newsletter, which cuts through the noise and misinformation to give you clear, accessible facts about the coronavirus, Ireland’s fight to contain it, as well as developments further afield.
This is your one-stop-shop for Covid news during a time when it can be hard or overwhelming to try and stay up to date with the latest.
You can read the full edition here, sign up to receive the newsletter here or at the bottom of the page.
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