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

Last updated: August 18, 2022

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The Public Health Agency of Canada established the Federal SARS-CoV-2 Variant Surveillance Group (FSVSG) 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 FSVSG has developed national definitions, designations, and public health actions for SARS-CoV-2 Variants of Interest (VOI), Variants of Concern (VOC), and De-escalated Variants. Descendent lineages inherit the classification of the parent lineage unless otherwise designated. Note that the VOI designation relates to surveillance status and is not a statement of the level of concern associated with a given variant.

Variant of concern (VOC)


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:


is otherwise assessed to be a VOC by the World Health Organization (WHO);


is otherwise assessed to be a VOC by the FSVSG.


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

Current variants of concern in Canada
WHO label Parent lineageTable 1 footnote * Designation date
Omicron B.1.1.529 November 28, 2021

Variant of interest


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;


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


is otherwise assessed to be a VOI by WHO;


is otherwise assessed to be a VOI by the FSVSG.


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

No currently circulating lineages are designated VOIs in Canada.


The SARS-CoV-2 virus continuously evolves, generating new lineages. Over time, some lineages may become prevalent while others will become extinct and no longer pose a threat to public health.

A VOC is de-escalated when:

A VOI is de-escalated as warranted after review by the FSVSG.

Variants that have been de-escalated after review by the FSVSG
WHO label Parent lineageTable 2 footnote * De-escalation date
Alpha B.1.1.7 August 18, 2022
Beta B.1.351 August 18, 2022
Gamma P.1 August 18, 2022
Delta B.1.617.2 August 18, 2022


November 12, 2021
Zeta P.2 September 09, 2021
Eta B.1.525 March 17, 2022
Theta P.3 December 09, 2021
Iota B.1.526 December 09, 2021
Kappa B.1.617.1 October 01, 2021
Lambda C.37 December 09, 2021
Mu B.1.621 February 17, 2022
n/a A.23.1 October 14, 2021
n/a B.1.1.318 January 27, 2022
n/a B.1.617.3 July 20, 2021

Risk assessments

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