10 June 2021 - WHO has assigned simple, easy to say and remember labels for key variants of SARS-CoV-2, the virus that causes COVID-19, using letters of the Greek alphabet.
These labels were chosen after wide consultation and a review of many potential naming systems. WHO convened an expert group of partners from around the world to do so, including experts who are part of existing naming systems, nomenclature and virus taxonomic experts, researchers and national authorities.
WHO will assign labels for those variants that are designated as Variants of Interest or Variants of Concern by WHO.
These labels do not replace existing scientific names (e.g. those assigned by GISAID, Nextstrain and Pango), which convey important scientific information and will continue to be used in research.
While they have their advantages, these scientific names can be difficult to say and recall, and are prone to misreporting. As a result, people often resort to calling variants by the places where they are detected, which is stigmatizing and discriminatory. To avoid this and to simplify public communications, WHO encourages national authorities, media outlets and others to adopt these new labels.
SARS-CoV-2 Variants of Concern and Variants of Interest, updated 31 May 2021
Variants of Concern
A SARS-CoV-2 variant that meets the definition of a VOI (see below) and, through a comparative assessment, has been demonstrated to be associated with one or more of the following changes at a degree of global public health significance:
Increase in transmissibility or detrimental change in COVID-19 epidemiology; or
Increase in virulence or change in clinical disease presentation; or
Decrease in effectiveness of public health and social measures or available diagnostics, vaccines, therapeutics.
Variants of Interest
A SARS-CoV-2 isolate is a Variant of Interest (VOI) if, compared to a reference isolate, its genome has mutations with established or suspected phenotypic implications, and either:
has been identified to cause community transmission/multiple COVID-19 cases/clusters, or has been detected in multiple countries; OR
is otherwise assessed to be a VOI by WHO in consultation with the WHO SARS-CoV-2 Virus Evolution Working Group.