Wednesday, March 17, 2021

UK PHE: Tracking 10th Variant (VUI-21MAR-02) - Nomenclature Change & Update On P.1 Variant

 
Countries reporting B.1.1.7 (aka VOC-20DEC-01) - Credit CDC

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The UK - which leads the world in genomic testing and surveillance of COVID cases - unsurprisingly also leads the world in finding, and identifying, new COVID variants. 

And for the second time in less than a week, the UK has announced the detection - and classification - of a new COVID VUI (Variant Under Investigation). 

From their announcement:
New Variant Under Investigation (VUI) designated

A new variant has been designated a Variant Under Investigation (VUI) by Public Health England (PHE).

On 9 March, PHE noted a report of 33 cases of a new variant reported by the Philippines. The variant includes a number of notable mutations including E484K and N501Y, which are found in several other Variants of Concern.

PHE has identified 2 cases of this variant in England. One of the cases is linked with international travel and the other is currently under investigation. All appropriate public health interventions are being undertaken.

This variant has been designated VUI-21MAR-02 (P.3). PHE and international partners continue to monitor the situation closely.
 
This now makes 10 VUIs (and/or VUCs `Variants of Concern') identified by the UK over the past 3 months. They are also monitoring a number of other `lesser' variants, including B.1.429, B.1.1.7 with S494P, A.27, and B.1.526.

By comparison, the United States - which does far less testing - is currently only publishing data on 3 Variants of Concern (B.1.1.7, B.1.351 & P.1).   So far, these are the three that have shown the most potential for disruption.  

Admittedly, the vast majority of COVID variants are destined to end up as little more than footnotes in the history of the pandemic. One or two may eventually rise to the top, while the rest will likely fall behind.  

The trick is separating out the pretenders from the contenders.  And as we've seen, that can change - sometimes abruptly - over time.

Yesterday the UK also announced the detection of two more P.1 COVID cases which are classified as a VOC (Variant of Concern), due to its increased transmissibility, and perceived ability to evade prior immunity.  

Two additional cases of Variant of Concern VOC-21JAN-02 (P.1) found in England

Two more cases of the Variant of Concern VOC-21JAN-02 (P.1) have been identified in England – one in the West Midlands and one in Haringey, London.

Both cases are linked with international travel to Brazil. The case in the West Midlands was identified following their arrival at Birmingham Airport, where they were tested and quarantined as part of the managed hotel quarantine process.

The London case was picked up through surge testing. Surge testing will be stepped up in the affected area, and contact tracing teams have undertaken a comprehensive investigation to identify any further contacts.

The latest cases bring the total number of P.1 variant cases in the UK to 12 – 9 in England and 3 in Scotland, all of which have links to travel or to a previously confirmed case that has travelled to Brazil. 

As revealing as the UK's genomic surveillance has been, it has also become a bit confusing. The UK uses a proprietary naming system, which has become increasingly cumbersome as the number of variants has risen.   

By now sharp-eyed readers will have noticed a change in the UK's nomenclature. The P.1 variant - which until yesterday was dubbed VOC-202101/02 is now VOC-21JAN-02, 

Yesterday the UK announced this revised nomenclature scheme, which - while still differing from what other nations use - is hoped will better identify variants. 

Changes in nomenclature

The previous variant names frequently include similar numbers with similar or repeating patterns. This makes referring to them verbally challenging. To overcome this challenge, a revised nomenclature has been agreed involving dropping the first 2 numbers of the year and replacing the 2-month numbers with a 3-letter abbreviation. This shortens the name and reduces the degree of repeated sequences of numbers. The table containing surveillance overview ‘UK total distribution’ contains a list of new variant names alongside previous or other names in use for VOCs and VUIs.


The UK's updated COVID surveillance chart (below) shows the 10 VOC/VUIs they are tracking as of March 15th, including their alternate names.  We should get more technical data on this latest addition in the next COVID Technical Briefing. 



While we shouldn't fret every time a new variant is identified somewhere in the world  - that happens several times a day - we can't ignore them either.  Most will fizzle, or are of no greater concern than the `wild type' COVID we've been dealing with for more than a year. 

Over time scientists should get better at identifying which are likely to be significant, and which are flashes in the pan.

But until then, surveillance systems will need to cast a wider net.