Another day, another variant. While the reaction to Omicron was immediate and one laced with genuine fear and concern, the emergence of a new strain in southeastern France has been met with a shrug of the shoulders by many scientists.
On paper, B.1.640.2 looks problematic. Like Omicron, it has multiple mutations, 46 in total, many of which are located in its spike protein – the part of the virus responsible for gaining entry to human cells.
In reality, this is a variant that predates Omicron yet has failed to take off globally in the same way.
It appears to have first popped up on scientists’ radars in early November, when the first sequenced case of B.1.640.2 was uploaded from Paris to a global variant database called Gisaid.
The first sequence of Omicron was uploaded three weeks later, on 22 November, and in the time that followed has spread rapidly across the world, reaching all six continents by the turn of the new year.
In contrast, B.1.640.2 appears to have been limited to minor clusters here and there, as seen in southeastern France where 12 people were infected with the variant, according to a non peer-reviewed study released before Christmas.
The ‘index case’ – the first individual identified at the heart of a cluster – was vaccinated against Covid and had returned from Cameroon three days before his positive result. The study claims he developed “mild” respiratory symptoms the day before his diagnosis.
However, when the scientists took a dive into Cameroon’s own genomic data, they were unable to find any sequences of B.1.640.2, suggesting the variant either hasn’t been detected in the country yet, or originated from elsewhere.
Perhaps it could be the case that the French traveller had a fleeting encounter with someone in an airport who was infected with B.1.640.2. At this stage, we simply don’t know.
Regardless, the alarm bells have yet to be rung when it comes to this particular variant.
Tom Peacock, a virologist at imperial College, said B.1.640.2 was “not one worth worrying about too much” at the moment. “This virus has had a decent chance to cause trouble but never really materialised,” he said on Twitter.
Other close viral cousins of B.1.640.2 have similarly been in circulation for weeks, but have also struggled to make an impact.
As to why it has this variant hasn’t been as successful in spreading as Omicron – despite its high mutation count – we can only speculate.
Although B.1.640.2 carries many of the same mutations seen in previous variants of concern, much depends on how they combine with one another to shape the characteristics of the virus.
It could be the case that some of the mutations are actually detrimental to the virus’ ability to enter our cells or replicate, thus hindering its ability to rapidly spread.
Data on B.1.640.2 is light, and until scientists have more of it, it’s unlikely they’ll be able to provide a clear answer as to why this particular variant hasn’t come to dominate.
Should that remain the case, it will ultimately be a good thing. For now, Omicron is the main variant of concern. Unless the picture changes considerably for whatever reason, that should be the predominant focus of our attention and scientific endeavours in the weeks to come.
