In order to shorten the 2-3 weeks between lineage spotting and annotation, @theosanderson has developed a tool that rapidly assigns genomes to the very latest lineages.
(I mention this because the data is slightly ahead of Monday's release using official annotation.)
This latest, provisional data includes a number of new lineages down to AY.120.2.1.
Another new lineage is AY.98 (green), which is rather numerous (n=11k samples) now comprising between 2%-5% of samples.
π¨βπ»: AY.98 is in fact a rather old branch of Delta and has been added mostly to complete the taxonomy.
It has been increasing slowly in all regions except the North East, where it's stagnant at higher levels. π€
π§βπ«: AY.98 was among the first founders of the Delta wave in N/E, reaching high numbers by chance. It now slowly diffuses to other regions until the frequencies are equal.
Lastly, there are also many currently uncharacterised variants across the π.
As the pandemic accelerates in regions such as Eastern Europe, variants from such places also appear in the UK in increasing numbers.
One example is the pink branch below, defined by Orf3a:202L. It doesn't have a pango lineage name yet.
In England Orf3a:202L is mostly found in London, where it rose noticeably to around 80 cases (2%) per day. These numbers are comparable to AY.4.2.1; the growth was even faster. π³
There are some signs now that XBB.1.5 is loosing steam as it spreads through the wider population.
The share of cases has increased more slowly in the US and UK, recently.
A speculative thread why this might be.
In slowing down XBB.1.5 follows a pattern that has been noted also for BQ.1.1 or XBB.1.1.
Their initial fitness (daily increase of variant share) was higher than their long term advantage in a multi-lineage model with constant differences between variants (coloured lines).
In fact this slowing was observed for almost every Omicron lineage.
There is large variation between countries though, in part because of the low numbers at low incidence.
But the trends are clear that the initial growth rates dropped down on average between 0.02 to 0.04.
* BQ.1.1 spreads, albeit at the low end of expectations
* XBB* and BQ* lineages are the most widespread
* Further new variants have been defined, including CK.2.1.1 leading to complex patterns
While the initial estimates of BQ.1.1's growth advantage to BA.5 were between 10-15%, the estimate has come down to ~10% more recently.
As other more transmissible variants such as BF.7 have also spread the current fitness is lower, around 6-7%.
CK.2.1.1 came a bit out of the blue but is also contributing a measurable share of cases in countries such as Spain (~9%) and Germany (~3%).
It spreads at a similar rate as BQ.1, which it also matches in terms of key RBD mutations as shown below