Another offshoot of the Delta variant is spreading in Britain, Covid-tracking experts revealed today — as the virus’ other concerning subvariant continues to spread.
According to the most recent data from one the country’s largest surveillance centers, the new sub-strain, AY.43 has been spotted 8,138 times in England.
It is estimated to make up one in 25 cases in Wales, the country where it is most common after being first detected in mid July and growing steadily.
Scientists today said there was no reason to be concerned about the strain. There was no evidence to suggest that it was more transmissible, or better able to evade vaccinations.
But it comes after a rapid uptick in cases of AY.4.2 — another descendant of the original Delta strain — which is being kept under close review by British and international scientists.
The AY.4.2 Subvariant is responsible for approximately 11% of all new England cases, according to the latest figures. It has been spotted only in five boroughs: Craven Burnley, Hyndburn Melton, Oadby and Wigston.
None of the sub-trains have been identified yet, but AY.4.2 could be called ‘Nu’ if it’s considered a threat to the World Health Organization (WHO), who is keeping an eye on its spread.
The graph above shows the percentage of cases that were down AY.43 (yellow), and AY.4.2(dark red). It also shows Alpha (purple), Delta (light green) and the old viruses (dark green, and pink). It shows that the proportion of cases below AY.4.2 has increased slightly in recent weeks.
The maps above show the spread of both AY.4.2 (left), and AY.43(right). AY.4.2 has reached every English local authority, except five, according to data from the largest Covid surveillance center in the country. AY.43 appears to be limited to London and the South East, but is still present in certain areas of the country. Both maps show the prevalence for the week ending October 23rd.
The graph below shows the number and severity of each week’s cases of Delta (purple), Alpha, and the old virus (light and dark pink), as well as the Delta offshoots AY.4.2 and AY.43. It shows a slight decrease in Delta, but a slight uptake among the subvariants.
AY.43 first became apparent in July, as Delta was taking off. There is no evidence to suggest that it is more dangerous or more able to evade vaccines. It is responsible for more cases in Europe, particularly France, where it accounted for half of the cases since September. It is a third in Germany, and a fifth in Denmark.
There are approximately 100 AY lineages, which are offshoots or derivatives of the Delta variant. However, the vast majority are not worrying.
AY.43 was first discovered in July as Delta was spreading throughout the globe. It is now much more common in Europe where it has been responsible for around half of all cases in France since September without triggering an increase in infections.
Globally, there have been 84,000 cases in 108 countries, with 7,000 in the US. Its true prevalence is likely to be much higher, as only a small percentage of samples are tested for variants and countries often do very little analysis.
Professor Lawrence Young, a Warwick Medical School virologist, stated today that there is no need to be concerned about AY.43, and experts should “just keep an eye” on it.
MailOnline was informed by him that the product had been around for a while and has not seen much success.
The subtype was discovered for the first time on British shores during July, when the more transmissible Delta variation was sparking a wave in infections across the country.
It was found to be at low levels by genomic surveillance and it took approximately four months for it to begin competing with other strains.
AY.43 is the only known mutation N:Q9L. Scientists call this ‘unusual’ but have yet to find any evidence that it makes it more transmissible, or more able to evade vaccines.
They claimed that the offshoot was likely imported from Europe to the UK, unlike the other Delta subvariant AY.4.2 which is believed have originated here. According to estimates, AY.43 is responsible for half of the cases in France, two-fifths in Belgium, and about a quarter in Germany.
Dr Jeffrey Barrett, who is the head of Covid surveillance at Sanger Institute, tweeted that ‘AY.43 may not be as widespread as AY.4.2 yet and is enriched only outside Greater London.
“This lineage is much more common in the UK, so these could be a variety introductions from abroad that have coincidentally increased a bit.
It has been growing in Germany, France, Belgium, Denmark and France. This could be a biological advantage or simply the fact that these countries are being hit with Delta case increase.
“[It]There are no spike mutations beyond Delta and only N:Q9L that appears to be unusual.
MailOnline spoke to Professor Young, who said that there is no need to be worried. He just recommends keeping an eye on the situation. Sublineages were always possible. The question is, why are we seeing any increase?
“Delta” seems to outcompete all others and still dominate. Its overwhelming transmissibility makes it impossible to destroy any other. [strains], and it just seems to dominate.
He said, “The virus spreads faster the more it is likely that it will change.” It is at high risk of generating variants.
“We have been facing problems in the last few months due to Delta. It is possible it will produce other variants, and that would be a disaster.
AY.43 was designated a subtype Delta because it had accounted to more than 80,000 global cases so far. The majority of these cases were in Europe.
There has been increased concern about the separate but identical offshoot AY.4.2. This was last week raised by health officials amid fears it may already have infected 150,000 Britons.
The UK Health Security Agency (UKHSA), who took over from the now-defunct Public Health England labeled the subtype as a ‘variant under examination’.
After rising from almost none at the beginning of September, outbreak.info data showed that it was now behind approximately four percent of England’s cases
France: It now accounts for 60 percent of cases, after arriving in France in August. However, the country has seen its cases drop over the same time, suggesting that the subtype is not more transmissible than other strains.
AY.43 is believed to be responsible for approximately two to three percent of all Covid infections in the United States.
It is responsible for around 30% of all infections in Germany, but this number is slowly falling.
This category is reserved to variants that are spreading in the UK and may be more transmissible, or better able evade vaccinations and other mutant strains. Mu, which was found in Colombia, is one of the other variants.
It is only one step away from a variant of concern’ label, which was already given to Alpha or Delta.
Scientists have suggested that AY.4.2 may be 10 to 15% more transmissible than its ancestor and will gradually replace the virus within the population over several months.
However, others at Northumbria University insist that the spread of the variant may be due to the “founder effect”, which is when a variant spreads because there is only one in a given area.
AY.4.2 first appeared in the UK in late-June in London and South East England, before spreading to the rest.