Tuesday, December 15, 2020

COG-UK: Brief Update & Expert Reaction On The New SARS-CoV-2 Variant In Southern England


#15,625

Yesterday, the UK Health Secretary Announced A New COVID Variant had been detected in Southern England, and while it doesn't appear to cause more serious disease than its predecessors, it is suspected to be more transmissible than previous strains. 

As a result of this finding, and the apparent rapid spread of this variant, the UK government announced that at midnight tonight a large swath of Southern England - including London, parts of Essex and Hertfordshire - would go into Tier 3 restrictions. 

Mutations and variant strains of COVID are nothing new, of course.  Most do little or nothing to affect the way the virus functions. But some have been problematic, including the D614G mutation which emerged in Europe shortly after COVID's arrival last winter and a more recent 20A.EU1 variant detected in Europe over the summer, both of which have been linked to increased transmissibility. 

Denmark has also reported at least 7 mink-variant COVID-19 strains, including one (`Cluster 5') which was feared to have changes that might make it less susceptible to the vaccine (see WHO 2nd Update: SARS-CoV-2 mink-associated variant strain – Denmark).

In mid-November Denmark's Serum Statens Institute  released a report suggesting this problematic `5th strain' - which might have affected vaccine effectiveness - appears to have been contained (see The recent development of covid-19 on mink farms and among humans).

Details on this new variant remain scant, but today we have some additional details from the COG-UK; the COVID-19 Genomics UK-Consortium.  I've only posted a brief excerpt, follow the link to read the report in its entirety.  

News
Update on new SARS-CoV-2 variant and how COG-UK tracks emerging mutations

COG-UK14 Dec 2020

Since its creation COG-UK has been supporting genomic surveillance efforts to identify variants of the SARS-CoV-2 virus in the genome sequencing data from the UK.

New SARS-CoV-2 variant

The variant described today in the House of Commons contains a novel set of mutations associated with a lineage spreading rapidly in the South East of England (and more widely) that is the subject of ongoing investigations by the UK Public Health Agencies, coordinated by Public Health England and supported by COG-UK. This variant carries a set of mutations including an N501Y mutation in the receptor binding motif of the Spike protein that the virus uses to bind to the human ACE2 receptor.

Efforts are under way to confirm whether or not any of these mutations are contributing to increased transmission. There is currently no evidence that this variant (or any other studied to date) has any impact on disease severity, or that it will render vaccines less effective, although both questions require further studies performed at pace. We will provide further updates as our investigations proceed.

How COG-UK is tracking emerging SARS-CoV-2 gene mutations

Explanation of terms:
  • Mutation is used to describe a replacement of a base in the genome, or a deletion or insertion event.
  • Viral variant refers to a distinct virus, which may have a combination of different mutations.
With the caveat that very little is publicly known right now about this new variant, The Science Media Centre has already compiled a long (and growing) list of expert reactions to this discovery.   As of this posting, 15 experts have weighed in.  

I've only posted three of the reactions, so follow the link below in order to get a wider range of perspectives.

DECEMBER 14, 2020
Expert reaction to the new variant of SARS-CoV-2

Matt Hancock announced that a new variant of SARS-CoV-2 has been identified in his speech to the House of Commons.


Dr Lucy van Dorp, senior research fellow in microbial genomics at the UCL Genetics Institute, said:

“It is frustrating to have claims like this made without the associated evidence presented for scientific assessment and the variant remains to be officially announced. It seems COG-UK will release further details soon1 and a preprint may follow2.
“The possible candidates based on some of our own observations (current as of 30th November) is that this may refer to a double deletion in the coronavirus spike protein (positions 69/70) or alternatively a spike mutation in the receptor binding domain N501Y3. There is some experimental support for N501Y increasing receptor binding experimental settings and mouse models. There have also been some reports that the spike double deletion has a moderate impact on antibody recognition.
“At the same time it is important to remember that all SARS-CoV-2 in circulation are extremely genetically similar to one another and our prior should be that most mutations have no significant impact on the transmissibility of SARS-CoV-2. However genomic monitoring is essential to allow us to stay one step ahead.”

Dr Simon Clarke, Associate Professor of Cellular Microbiology at the University of Reading, said:
“Health Secretary Matt Hancock has linked the discovery of a mutation in the virus’ spike protein to increased transmission; while that is yet to be verified, it would be of grave concern if it indeed proves to be the case. While Hancock states that there is “nothing to suggest” this variant will cause more serious disease, if it spreads more readily than other versions, infecting more people, it could eventually take a bigger toll on human health.”

Dr Zania Stamataki, Viral Immunologist, University of Birmingham, said:

“The emergence of different coronavirus strains a year after SARS-CoV-2 first jumped to humans is neither cause for panic nor unexpected. Mutations will accumulate and lead to new virus variants, pushed by our own immune system to change or perish.
“This virus doesn’t mutate as fast as influenza and, although we need to keep it under surveillance, it will not be a major undertaking to update the new vaccines when necessary in the future. This year has seen significant advances take place, to build the infrastructure for us to keep up with this coronavirus.”

 

If there is a bottom line at this point, it is probably that it is too soon to know how much of an impact - if any - this new variant (or others that will inevitably follow) will have on the course of the pandemic. 

We shouldn't be surprised, however, to see more reports like this, as viruses must evolve in order to survive in the face of expanding community immunity. An evolutionary pressure that will only increase as more people recover from, or are immunized, against the virus.

Stay tuned.