Research and analysis

Variants: distribution of case data, 23 December 2021

Updated 24 June 2022

Variants of concern or under investigation: data up to 22 December 2021

Surveillance overview

UK total distribution

Variant* Other names by which this variant may be known** Lineage Total confirmed (sequencing) and probable (genotyping) cases New cases since last update (data up to 15 December)
Alpha VOC-20DEC-01 B.1.1.7 277,629 +122
Beta§ VOC-20DEC-02 B.1.351 1,110§ -1
Gamma VOC-21JAN-02 P.1 285 -8
Delta VOC-21APR-02 B.1.617.2 AY.1 AY.2 1,672,658 +47,101
VUI-21OCT-01*** VUI-21OCT-01 A.Y 4.2 108,507 +12,007
Omicron VOC-21NOV-01 B.1.1.529 90,906 +80,889
Zeta VUI-21JAN-01 P.2 57 0
VUI-21FEB-03 VUI-21FEB-03 B.1.525 (previously designated UK1188) 514 0
VUI-21FEB-04 VUI-21FEB-04 B.1.1.318 366 0
Theta VUI-21MAR-02 P.3 10 0
Kappa VUI-21APR-01 B.1.617.1 521 +1
VUI-21APR-03 VUI-21APR-03 B.1.617.3 18 0
VUI-21MAY-02 VUI-21MAY-02 C.36.3 158 +1
Lambda VUI-21JUN-01 C.37 8 -1
Mu§ VUI-21JUL-01 B.1.621 59§ +1

*Information pertaining to VUI-21MAR-01, B1.324.1 with E484K has been removed as this variant has been reclassified as provisionally extinct. Variants VUI-21FEB-01 (A.23.1 with E484K), and VOC-21FEB-02 (Alpha with E484K) are provisionally extinct (not detected for 12 weeks in the UK or in GISAID) therefore they will no longer be included in the publication from 12 November 2021. Variant VUI-21MAY-01, AV.1 has been removed as of 3 December 2021 as it has been classified as provisionally extinct.

**WHO naming has been included where available.

† Of which 678 had the K417N mutation.

Confirmed individuals are confirmed COVID-19 cases with a validated sequencing result meeting the confirmed case definitions outlined in the sections below. Probable individuals are confirmed COVID-19 cases with a genotyping result where sequencing confirmation is awaited or not available. Published figures include genotyping assay data for England, using a combination of highly specific mutations as an indicator of a probable variant. Genotyping assay data is currently only available for Alpha, Beta (for specimen dates up to and including 30 June 2021), Delta and Gamma.

§Due to having identical genotyping profiles, since 1 July Beta and Mu cases identified by genotyping have been categorised as ‘Beta or Mu’. In addition to the above numbers, a further 17 ‘Beta or Mu’ provisional genotyping cases have been identified.

***Confirmed VOC-21APR-02 with at least 2 VUI-21OCT-01 lineage defining positions called as alternate (variant) base and all other defining positions reported as N (unknown) or mixed bases.

There will be no ‘COVID-19 variants: genomically confirmed case numbers’ publication on 31 December. The publication will resume as normal the following week, on 7 January 2022.

Differences between a variant of concern and a variant under investigation

SARS-CoV-2 variants, if considered to have concerning epidemiological, immunological or pathogenic properties, are raised for formal investigation. At this point they are designated variant under investigation (VUI) with a year, month, and number. Following a risk assessment with the relevant expert committee, they may be designated variant of concern (VOC).

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.

Alpha

Surveillance overview

This variant was first detected in the UK and was first sequenced in the UK in September 2020.

Total confirmed and probable cases
England 226,866
Northern Ireland 9,166
Scotland 29,129
Wales 12,468
Total cases 277,629

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with at least 5 VOC-20DEC-01 lineage defining positions are called as alternate (variant) base and all other defining positions reported as N (unknown) or mixed bases
Probable (genotyping) COVID-19* confirmed case with a genotyping result where sequencing confirmation is awaited or not available
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Beta

Surveillance overview

This variant was first detected in South Africa and was first sequenced in the UK in December 2020.

Total confirmed and probable cases
England 996
Northern Ireland 9
Scotland 62
Wales 43
Total cases 1,110

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case where:
• at least 4 VOC-20DEC-02 lineage defining positions are called as alternate (variant) base, and
• all other defining positions reported as N (unknown) or mixed bases 
or
• at least 5 of the 9 non-synonymous changes
Probable (genotyping) COVID-19* confirmed case with a genotyping result where sequencing confirmation is awaited or not available
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Gamma

Surveillance overview

This variant was first detected in Japan in travellers from Brazil in January 2021 and was first detected in the UK in February 2021.

Total confirmed and probable cases
England 260
Northern Ireland 0
Scotland 23
Wales 2
Total cases 285

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with:
• at least 5 lineage defining non-synonymous changes called as alternate base, and
• all other positions either N or mixed bases
Probable (genotyping) COVID-19* confirmed case with a genotyping result where sequencing confirmation is awaited or not available
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Delta

Surveillance overview

Total confirmed and probable cases
England 1,364,061
Northern Ireland 91,188
Scotland 129,405
Wales 88,004
Total cases 1,672,658

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with at least 4 variant defining changes called as alternate base
Probable (genotyping) COVID-19* confirmed case with a genotyping result where sequencing confirmation is awaited or not available
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

VUI-21OCT-01

Surveillance overview

Total confirmed and probable cases
England 83,046
Northern Ireland 676
Scotland 11,324
Wales 13,461
Total cases 108,507

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case that is confirmed VOC-21APR-02 with at least 2 VUI-21OCT-01 lineage defining positions called as alternate (variant) base and all other defining positions reported as N (unknown) or mixed bases.
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Omicron

Surveillance overview

Total confirmed and probable cases
England 83,526
Northern Ireland 3,877
Scotland 2,326
Wales 1,177
Total cases 90,906

Cases by LTLA

Confirmed Omicron and S-gene target failure cases by local authority.

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with at least 10 lineage defining non-synonymous changes called as alternate base and no more than 7 defining positions called as wild-type
Probable (genotyping) COVID-19* confirmed case with a genotyping result where sequencing confirmation is awaited or not available
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).  

Zeta

Surveillance overview

This variant was first detected in Brazil and was first sequenced in the UK in November 2020.

Total confirmed and probable cases
England 51
Northern Ireland 0
Scotland 5
Wales 1
Total cases 57

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* case confirmed as infected with VUI-21JAN-01 through whole genome sequencing (WGS) where:
• results of all lineage defining non-synonymous changes called as alternate base
or
• 6 of 7 non-synonymous changes called as alternate base, and
• remaining position either N or mixed bases
Probable (genotyping) COVID-19* confirmed case with a genotyping result where sequencing confirmation is awaited or not available
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

VUI-21FEB-03

Surveillance overview

This variant was first detected in the UK in December 2020.

Total confirmed and probable cases
England 462
Northern Ireland 2
Scotland 40
Wales 10
Total cases 514

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with:
• at least 5 lineage defining non-synonymous changes called as alternate base, and
• all other positions either N or mixed bases
Probable (genotyping) COVID-19* confirmed case with a genotyping result where sequencing confirmation is awaited or not available
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

VUI-21FEB-04

Surveillance overview

This variant was first detected in the UK (England).

Total confirmed and probable cases
England 315
Northern Ireland 40
Scotland 11
Wales 0
Total cases 366

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with:
• at least 5 lineage defining non-synonymous changes called as alternate base, and
• all other positions either N or mixed base
or
• at least 5 of the 9 non-synonymous changes
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Theta

Surveillance overview

This variant was first detected in the Philippines.

Total confirmed and probable cases
England 7
Northern Ireland 0
Scotland 3
Wales 0
Total cases 10

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with:
• at least 7 variant defining changes called as alternate base, and
• all other positions either N or mixed base
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Kappa

Surveillance overview

This variant was first detected in India.

Total confirmed and probable cases
England 475
Northern Ireland 4
Scotland 27
Wales 15
Total cases 521

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with:
• at least 6** variant defining changes called as alternate base, and
• all other positions either N or mixed base
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).
**Due to overlap with Delta sequences, the case definition of Kappa sequences was changed on 27 August 2021.

VUI-21APR-03

Surveillance overview

This variant was first detected in India.

Total confirmed and probable cases
England 15
Northern Ireland 0
Scotland 0
Wales 3
Total cases 18

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with:
• at least 8 variant defining changes called as alternate base, and
• all other positions either N or mixed base
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

VUI-21MAY-02

Surveillance overview

This variant was first detected in Thailand (in travellers from Egypt).

Total confirmed and probable cases
England 147
Northern Ireland 3
Scotland 4
Wales 4
Total cases 158

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with at least 5 variant defining changes called as alternate base, and
• all other positions either N or mixed base.
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Lambda

Surveillance overview

This variant was first detected in Peru in August 2020.

Total confirmed and probable cases
England 8
Northern Ireland 0
Scotland 0
Wales 0
Total cases 8

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with at least 5 VUI-21JUN-01 lineage defining positions are called as alternate (variant) base and all other defining positions reported as N (unknown) or mixed bases.
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).

Mu

Surveillance overview

Total confirmed and probable cases
England 53
Northern Ireland 2
Scotland 3
Wales 1
Total cases 59

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* confirmed case with at least 5 VUI-21JUL-01 defining mutations called as alternate (variant) base and all other defining positions reported as N (unknown) or mixed bases.
*A confirmed COVID-19 case: a case where the individual is confirmed to be infected with SARS-CoV-2 by polymerase chain reaction (PCR).