A new Covid sub-variant that can evade immunity could now account for one in 11 of all current infections in England, according to the latest briefing from the UK Health Security Agency.
BA.4.6, the not-so-catchy scientific name for this new strain of Omicron (BA.5), was first identified on August 15 but has since spread at an increasing rate across England, tripling to 9 per cent of all sequenced cases as of the most recent data.
There are currently 1,697 cases of BA.4.6 identified in England, though this number only represents the number of infections both tested for and genetically sequenced, not in the general population.
Worryingly, early viral analysis suggests that the newly spreading sub-variant has an infectious edge over the currently dominant strain of Covid (BA.5), indicating that this new type of Omicron could be here to stay.
With Covid data experts warning of an incoming wave of infection, this is everything you need to know about the new BA.4.6 sub-variant.
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What is different about this new BA.4.6 strain of Omicron?
As viruses replicate and spread, their genetic code can mutate and cause them to change. Many of these mutations will have little effect on the virus, but some can cause them to spread more quickly, or even evade detection by our immune systems.
When Omicron emerged at the tail-end of 2021, it quickly became the dominant form of Covid infecting people around the world. Thankfully, though it spread more rapidly than the previous Delta variant it also caused fewer hospitalisations and deaths.
What caused scientists to identify this new Omicron sub-variant as one of note is a mutation in one of its spike proteins, a part of the virus that allows it to gain entry to our cells. This mutation could help it to evade detection, even in people who have received a full course of covid vaccination.
In an Oxford University trial, scientists found that people who were triple-vaccinated produced fewer virus-killing antibodies in response to BA.4.6 over other variants - reducing the effectiveness of vaccines against this new strain.
There is no evidence that infections of this new sub-variant are any more dangerous than the dominant Omicron strain.
Where in the UK has the most cases of the BA4.6 variant?
Identified cases of the BA.4.6 variant are not evenly distributed across England, according to the UKHSA.
Of the 1,697 identified Centaurus cases, a large proportion has been discovered in the North West of England, while previous infection hotspot London has seen the least amount of new variant cases.
As of September 6, these are the numbers of identified BA.4.6 cases in England, per region.
- North West - 458
- Yorkshire and Humber - 197
- West Midlands - 181
- South East - 145
- South West - 141
- North East - 113
- East of England - 105
- London - 102
- Unidentified region - 153
Where in the world has the most cases of the new BA.4.6 variant?
Though the first identified and genomically sequenced case of BA.4.6 was in South Africa, the vast majority of current infections are taking place across western countries.
The UK and US are both seeing a spike in new variant infections, with cases increasing by more than a third in both countries.
As of the most recent UKHSA data, these are the numbers of identified BA.4.6 cases around the world, per country.
- United States of America - 9,526
- United Kingdom - 1,697
- Canada - 1,007
- Denmark - 500
- France - 400
- Australia - 288
- Germany - 248
- Chile - 242
- Dominican Republic - 173
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