SARS-CoV-2 variants: National definitions, classifications and public health actions

Last updated: July 21, 2021

On this page

Preamble

The Public Health Agency of Canada, in collaboration with provincial and territorial public health authorities, established the Canadian SARS-CoV-2 Variant Surveillance Group (CSVSG) to monitor and assess the impact of variants of SARS-CoV-2 on viral transmissibility, disease severity, and efficacy of vaccines, therapeutics, and diagnostics. The CSVSG has developed national definitions, classifications, and public health actions for SARS-CoV-2 Variants of Interest (VOI) and Variants of Concern (VOC).

Variant of interest

Definition

A SARS-CoV-2 variant is a VOI if it

has a genome with mutations associated with changes in epidemiology, antigenicity, or virulence, or changes that potentially have a negative impact on available diagnostics, vaccines, therapeutics, or public health measures;

and

is known to cause community transmission/multiple COVID-19 cases/clusters in Canada or has been detected in multiple countries;

or

is otherwise assessed to be a VOI by WHO;

or

is otherwise assessed to be a VOI by the CSVSG.

Actions

If a variant is determined to be a VOI, actions may include the following:

Table 1. Variants of interest. Updated July 21, 2021
WHO label Pango lineage Attributes Designation date
Epsilon B.1.427
B.1.429

Evidence of increased transmissibility Footnote 1

Evidence of moderate neutralization by some monoclonal antibody therapies Footnote 2

May 14, 2021
Zeta P.2

Predicted reduction in neutralization by some monoclonal antibody therapies

Predicted reduction in neutralization by polyclonal antibodies in convalescent sera

May 14, 2021
Eta B.1.525

Evidence of increased transmissibility Footnote 1

Predicted reduction in neutralization by some monoclonal antibody therapies

Predicted reduction in neutralization by polyclonal antibodies in convalescent sera

May 14, 2021
Theta P.3

Predicted reduction in neutralization by some monoclonal antibody therapies

Predicted reduction in neutralization by polyclonal antibodies in convalescent sera

May 14, 2021
Iota B.1.526
B.1.526.1

Evidence of increased transmission Footnote 1

Predicted reduction in neutralization by some monoclonal antibody therapies

Predicted reduction in neutralization by polyclonal antibodies in convalescent sera

May 14, 2021
Kappa B.1.617.1 Evidence of increased transmission Footnote 1
Preliminary evidence of impact on neutralization by convalescent and post-vaccination sera Footnote 3, Footnote 4
July 20, 2021
Lambda C.37 Preliminary evidence of moderate reduction in neutralization by convalescent and post-vaccine sera Footnote 5 July 20, 2021
n/a A.23.1

Predicted reduction in neutralization by some monoclonal antibody therapies

Predicted reduction in neutralization by polyclonal antibodies in convalescent sera

May 14, 2021
n/a B.1.1.318

Predicted reduction in neutralization by some monoclonal antibody therapies

Predicted reduction in neutralization by polyclonal antibodies in convalescent sera

May 14, 2021
n/a B.1.617.3

Predicted impact on neutralization by polyclonal antibodies

Predicted impact on neutralization by convalescent sera and post-vaccination sera

July 20, 2021

Variant of concern

Definition

A SARS-CoV-2 variant is a VOC if, through a comparative assessment, it has been demonstrated to be associated with one or more of the following:

or

is otherwise assessed to be a VOC by WHO;

or

is otherwise assessed to be a VOC by the CSVSG.

Actions

If a variant is determined to be a VOC, actions may include the following:

Table 2. Variants of concern. Updated July 21, 2021
WHO label Pango lineage Attributes Designation date
Alpha B.1.1.7 Evidence of increased transmission
Footnote 1
Evidence of increased severity Footnote 6,
Footnote 7

Evidence of reduced neutralization by convalescent sera and post-vaccination sera Footnote 8Footnote 9Footnote 10
May 14, 2021
Beta B.1.351
B.1.351.1
B.1.351.2
B.1.351.3
B.1.351.4
Evidence of increased transmission
Footnote 1
Evidence of increased severity Footnote 11
Evidence of impact on neutralization by polyclonal antibodies Footnote 2
Evidence of reduced neutralization by convalescent sera and post-vaccination sera
Footnote 12,Footnote 8Footnote 13
May 14, 2021
Gamma P.1
P.1.1
P.1.2
Evidence of increased transmission
Footnote 1
Evidence of increased severity Footnote 14,
Footnote 15
Evidence of impact on neutralization by polyclonal antibodies Footnote 2
Evidence of reduced neutralization by convalescent sera and post-vaccination sera
Footnote 16
May 14, 2021
Delta B.1.617.2
AY.1
AY.2
Evidence of increased transmission
Footnote 1
Evidence of increased severity Footnote 17,
Footnote 18
Evidence of impact on neutralization by polyclonal antibodies Footnote 3Footnote 4
Evidence of reduced neutralization by convalescent sera and post-vaccination sera
Footnote 8Footnote 9
July 20, 2021

References

Campbell

Campbell
Campbell, F et al. (2021) Increased transmissibility and global spread of SARS-CoV-2 variants of concern as at June 2021. Eurosurveillance doi: https://doi.org/10.2807/1560-7917.ES.2021.26.24.2100509

Retour à la référence de la note de bas de page 1

FDA des É.-U.

US FDA
US FDA (2021) U. S. Fact sheet for health care providers emergency use authorization (Eua) of bamlanivimab and etesevimab. https://www.fda.gov/media/145802/download

Retour à la référence de la note de bas de page 2

Hoffmann

Hoffmann
Hoffmann, M. et al. (2021) SARS-CoV-2 variant B.1.617 is resistant to Bamlanivimab and evades antibodies induced by infection and vaccination. bioRxiv, doi: https://doi.org/10.1101/2021.05.04.442663

Retour à la référence de la note de bas de page 3

Liu

Liu
Liu, C. et al. (2021) Reduced neutralization of SARS-CoV-2 B.1.617 by vaccine and convalescent serum. Cell, doi: https://doi.org/10.1016/j.cell.2021.06.020

Retour à la référence de la note de bas de page 4

Tada

Tada
Tada, T. et al. (2021) SARS-CoV-2 Lambda Variant Remains Susceptible to Neutralization by mRNA Vaccine-elicited Antibodies and Convalescent Serum. bioRxiv, doi: https://doi.org/10.1101/2021.07.02.450959

Retour à la référence de la note de bas de page 5

Davies

Davies
Davies, N. G. et al. (2021) Increased mortality in community-tested cases of SARS-CoV-2 lineage B.1.1.7. Nature doi: https://doi.org/10.1038/s41586-021-03426-1

Retour à la référence de la note de bas de page 6

Challen

Challen
Challen, R. et al. (2021) Risk of mortality in patients infected with SARS-CoV-2 variant of concern 202012/1: matched cohort study. BMJdoi: http://doi.org/10.1136/bmj.n579

Retour à la référence de la note de bas de page 7

Nasreen

Nasreen
Nasreen, S. et al. (2021) Effectiveness of COVID-19 vaccines against variants of concern, Canada. medRxiv, doi: https://doi.org/10.1101/2021.06.28.21259420

Retour à la référence de la note de bas de page 8

Bernal

Bernal
Bernal, J. L. et al. (2021) Effectiveness of COVID-19 vaccines against the B.1.617.2 variant. medRxiv, doi: https://doi.org/2021.05.22.21257658

Retour à la référence de la note de bas de page 9

Cele

Cele
Cele, S. et al. (2021) Escape of SARS-CoV-2 501Y.V2 from neutralization by convalescent plasma. Nature, doi: https://doi.org/10.1038/s41586-021-03471-w

Retour à la référence de la note de bas de page 10

Jassat

Jassat
Jassat, W. et al. (2021) Increased mortality among individuals hospitalised with COVID-19 during the second wave in South Africa. bioRxiv, doi: https://doi.org/10.1101/2021.03.09.21253184

Retour à la référence de la note de bas de page 11

Mahdi

Madhi
Madhi, S. A. et al. (2021)Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant. N. Engl. J. Med. doi: https://doi.org/10.1056/NEJMoa2102214

Retour à la référence de la note de bas de page 12

Lustig

Lustig
Lustig, Y. et al. (2021) Neutralizing Response against Variants after SARS-CoV-2 Infection and One Dose of BNT162b2. N. Engl. J. Med., doi: https://doi.org/10.1056/NEJMc2104036

Retour à la référence de la note de bas de page 13

Funk

Funk
Funk, T. et al. (2021) Characteristics of SARS-CoV-2 variants of concern B.1.1.7, B.1.351 or P.1: data from seven EU/EEA countries, weeks 38/2020 to 10/2021. Eurosurveillance, doi:https://doi.org/10.2807/1560-7917.ES.2021.26.16.2100348

Retour à la référence de la note de bas de page 14

Freitas

Freitas
Freitas, A. R. R. et al. (2021) The increase in the risk of severity and fatality rate of covid-19 in southern Brazil after the emergence of the Variant of Concern (VOC) SARS-CoV-2 P.1 was greater among young adults without pre-existing risk conditions. bioRxiv, doi: https://doi.org/10.1101/2021.04.13.21255281

Retour à la référence de la note de bas de page 15

Wang

Wang
Wang, P. et al. (2021) Increased Resistance of SARS-CoV-2 Variant P.1 to Antibody Neutralization. CSHL, doi: https://doi.org/10.1101/2021.03.01.433466

Retour à la référence de la note de bas de page 16

Sheikh

Sheikh
Sheikh, A. et al. (2021) SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospital admission, and vaccine effectiveness. Lancet, doi :https://doi.org/10.1016/S0140-6736(21)01358-1

Retour à la référence de la note de bas de page 17

Ong

Ong
Ong, S. W. X., et al. (2021). Clinical and Virological Features of SARS-CoV-2 Variants of Concern: A Retrospective Cohort Study Comparing B.1.1.7 (Alpha), B.1.315 (Beta), and B.1.617.2 (Delta). SSRN, doi: https://doi.org/10.2139/ssrn.3861566

Retour à la référence de la note de bas de page 18

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: