Research and analysis

Variants: distribution of case data, 8 October 2021

Updated 24 June 2022

Variants of concern or under investigation: data up to 6 October 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 29 September)
Alpha VOC-20DEC-01 B.1.1.7 278,100 -15
Beta§ VOC-20DEC-02 B.1.351 1,106§ -11
Delta† VOC-21APR-02 B.1.617.2 AY.1 AY. 2 933,404† +74,666
VOC-21FEB-02 VOC-21FEB-02 B.1.1.7 with E484K 46 0
Gamma VOC-21JAN-02 P.1 288 0
Kappa VUI-21APR-01 B.1.617.1 519 0
VUI-21APR-03 N/A B.1.617.3 18 0
VUI-21FEB-01 VUI-21FEB-01 A.23.1 with E484K 79 0
Eta VUI-21FEB-03 B.1.525 (previously designated UK1188) 512 0
VUI-21FEB-04 VUI-21FEB-04 B.1.1.318 369 -6
Zeta VUI-21JAN-01 P.2 60 0
Theta VUI-21MAR-02 P.3 10 0
VUI-21MAY-01 N/A AV.1 185 0
VUI-21MAY-02 N/A C.36.3 159 0
Lambda VUI-21JUN-01 C.37 9 0
Mu§ VUI-21JUL-01 B.1.621 55§ 0

*Information pertaining to VUI-21MAR-01, B1.324.1 with E484K has been removed as this variant has been reclassified as provisionally extinct.

**WHO naming has been included where available.

† Of which 205 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 2021 VOC-20DEC-02 and VUI-21JUL-01 cases identified by genotyping have been categorised as ‘VOC-20DEC-02 or VUI-21JUL-01’. In addition to the above numbers, a further 12 ‘VOC-20DEC-02 or VUI-21JUL-01’ provisional genotyping cases have been identified.

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 227,340
Northern Ireland 9,163
Scotland 29,129
Wales 12,468
Total cases 278,100

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 992
Northern Ireland 9
Scotland 62
Wales 43
Total cases 1,106

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).

Delta

Surveillance overview

Total confirmed and probable cases
England 762,248
Northern Ireland 48,893
Scotland 84,969
Wales 37,294
Total cases 933,404

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).

VOC-21FEB-02

Surveillance overview

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

Total confirmed and probable cases
England 45
Northern Ireland 1
Scotland 0
Wales 0
Total cases 46

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
COVID-19* case confirmed as infected with VOC-21FEB-02 through whole genome sequencing (WGS) where results of all lineage defining non-synonymous changes called as alternate 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).

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 263
Northern Ireland 0
Scotland 23
Wales 2
Total cases 288

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).

Kappa

Surveillance overview

This variant was first detected in India.

Total confirmed and probable cases
England 473
Northern Ireland 4
Scotland 27
Wales 15
Total cases 519

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-21FEB-01

Surveillance overview

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

Total confirmed and probable cases
England 79
Northern Ireland 0
Scotland 0
Wales 0
Total cases 79

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).

Eta

Surveillance overview

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

Total confirmed and probable cases
England 460
Northern Ireland 2
Scotland 40
Wales 10
Total cases 512

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
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 43
Scotland 11
Wales 0
Total cases 369

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).

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 54
Northern Ireland 0
Scotland 5
Wales 1
Total cases 60

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).

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).

VUI-21MAY-01

Surveillance overview

This variant was first detected in the UK in May 2021.

Total confirmed and probable cases
England 184
Northern Ireland 0
Scotland 0
Wales 1
Total cases 185

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).

VUI-21MAY-02

Surveillance overview

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

Total confirmed and probable cases
England 148
Northern Ireland 3
Scotland 4
Wales 4
Total cases 159

Case definitions

Genomic match Criteria
Confirmed
(sequencing)
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 1
Scotland 0
Wales 0
Total cases 9

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 49
Northern Ireland 2
Scotland 3
Wales 1
Total cases 55

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).