UK: The Alpha variant rears its ugly head again

A big surprise in the latest UK sequencing figures show that the Alpha variant has made something of a comeback this week. Even though the percentage of Alpha cases is still tiny compared to that of Delta, the figure of more than 400 Alpha cases is the highest since mid-June 2021.

It’s unclear whether this is a localised outbreak (it may be part of the unfolding superspreader event of the Boardmasters festival in Cornwall for example), or whether these are cases scattered across the UK, but to see such a resurgence after so many weeks of Delta dominance is something of a shock as the Alpha variant was far less effective at breaking through vaccine protection than the Delta variant is.

After weeks of just a handful of Alpha cases in the UK, there is suddenly a spike of over 400 new cases:


Confirmation that the Delta variant has dipped recently:

Charts and data courtesy of




Image by Josch13 from Pixabay

Delta attempting to brute-force its way past the human immune system

The Delta variant of Sars-CoV-2 seems to have taken a leaf from a computer hacker’s manual by attempting to brute-force its way past human and vaccine immunity systems by spitting out slightly mutated versions of itself almost on a daily basis.

Similar to cracking a password, brute-forcing means that the virus is trying every possible combination of variations to find the most effective one, and it’s doing it incredibly quickly. The most successful new mutations then become dominant through selection pressure.

Many of these new Delta plus variants are distinguishable only by a single mutation, but the brute-force technique the virus is now using represents the biggest threat to humanity so far, as we have no obvious means to prevent it.

For example, two weeks ago, we took a snapshot of that showed a big rise in the AY.3 Delta plus variant in the USA.


Now, just two weeks later, the AY.3 variant has already been supplanted by the AY.4 variant:




The number of Delta plus variants seems to be rising ever more quickly, each variant with its own individual key combination to try to pick the immunity lock. With no lockout mechanism for failed attempts, the virus can just keep trying until it succeeds.

Here’s a list of the Delta Plus variants so far, taking us up to AY.15, with many more to be added soon we’re sure:

AY.1 United States of America 44.0%, Portugal 10.0%, United Kingdom 10.0%, Japan 10.0%, Switzerland 7.0% 2021-04-07 243 562 Alias of B.1.617.2.1, in several European countries, from pango-designation issue #95

AY.2 United States of America 99.0%, Mexico 0.0%, Spain 0.0%, Aruba 0.0%, Albania 0.0% 2021-03-31 201 1232 Alias of B.1.617.2.2, in USA with K417N, from pango-designation issue #107

AY.3 United States of America 98.0%, Mexico 1.0%, United Kingdom 0.0%, Japan 0.0%, Germany 0.0% 2021-04-13 846 7503 Alias of B.1.617.2.3, USA lineage, from pango-designation issue #121

AY.3.1 United States of America 100.0%, India 0.0% 2021-05-18 197 983 Alias of B.1.617.2.3.1, USA lineage, from pango-designation issue #147

AY.4 United Kingdom 68.0%, United States of America 12.0%, Denmark 3.0%, Spain 2.0%, France 2.0% 2021-01-05 3684 152304 Alias of B.1.617.2.4, UK lineage, from pango-designation issue #180

AY.5 United Kingdom 68.0%, Portugal 12.0%, Spain 4.0%, France 4.0%, Ireland 3.0% 2021-04-15 436 6837 Alias of B.1.617.2.5, UK lineage, from pango-designation issue #180

AY.6 United Kingdom 79.0%, United States of America 8.0%, Ireland 2.0%, Italy 2.0%, Denmark 1.0% 2021-01-08 201 7007 Alias of B.1.617.2.6, UK lineage, from pango-designation issue #180

AY.7 Denmark 71.0%, United Kingdom 23.0%, Italy 3.0%, France 1.0%, Germany 1.0% 2021-05-01 134 6417 Alias of B.1.617.2.7, UK lineage, from pango-designation issue #180

AY.7.1 4624 0 Alias of B.1.617.2.7.1, Denmark lineage

AY.7.2 342 0 Alias of B.1.617.2.7.2, predominantly Italy lineage in multiple other European countries

AY.8 United Kingdom 100.0%, Australia 0.0%, Belgium 0.0% 2021-04-20 703 707 Alias of B.1.617.2.8, UK lineage, from pango-designation issue #180

AY.9 United Kingdom 64.0%, Denmark 11.0%, Germany 5.0%, Switzerland 4.0%, Belgium 3.0% 2021-04-01 322 6892 Alias of B.1.617.2.9, UK lineage, from pango-designation issue #180

AY.10 United Kingdom 73.0%, Canada 8.0%, United States of America 7.0%, Gambia 5.0%, France 2.0% 2021-04-12 71 771 Alias of B.1.617.2.10, UK lineage, from pango-designation issue #180

AY.11 United Kingdom 33.0%, United States of America 16.0%, South_Africa 11.0%, Turkey 10.0%, Ireland 6.0% 2021-02-06 522 2138 Alias of B.1.617.2.11, UK lineage, from pango-designation issue #142

AY.12 Denmark 11.0%, United States of America 11.0%, United Kingdom 10.0%, Germany 10.0%, Israel 7.0% 2020-09-07 579 26845 Alias of B.1.617.2.12, Israel lineage, from pango-designation issue #170

AY.15 94 0 Alias of B.1.617.2.15, Canada lineage

Lineage information courtesy of


USA: AY.3 genomes increasing faster than Delta B.1.617.2

USA/UK: 2 separate clades of Delta #coronavirus variant with K417N – AY.1 and AY.2

Through routine scanning of variation in Delta, a small number of sequences were detected which had acquired the spike protein mutation K417N. Information suggests that there are at least 2 separate clades of Delta with K417N. One clade is large and internationally distributed with PANGO lineage designation AY.1.  A second clade found in sequences uploaded to GISAID from the USA, now designated AY.2.

As of 16 June 2021, 161 genomes of Delta-AY.1 have been identified on GISAID. from Canada (1), India (8), Japan (15), Nepal (3), Poland (9), Portugal (22), Russia (1), Switzerland (18), Turkey (1), USA (83).

There are currently 38 cases of Delta-AY.1 in England (36 confirmed sequencing and 2 probable genotyping). Cases have been detected in 6 different regions in England. Delta-AY.2 has not been detected in England.

UK Variants of Concern Technical Briefing 15 (PDF download)


According to Bani Jolly of the Institute of Genomics and Integrative Biology, the phylogeny of Delta has two separate clades. While AY.1 is found in a few countries including the UK, India and Nepal, the other clade (AY.2), is largely from the sequences from California (USA).

“The split between the two clades seems to be based on two spike mutations — A222V and T95I. While all sequences in the California cluster share spike A222V, all sequences in the larger international cluster share spike T95I,” Jolly tweeted.

Stating that AY.1 has arisen independently a number of times and could be more prevalent than observed in countries with limited genomic surveillance, she tweeted that given that Delta is a variant of concern, it is important to take note of any sub-lineages that may emerge.

Time of India report




Image by PublicDomainPictures from Pixabay