Variants of Concern vs. Variants of Interest
Variants of concern (VOCs) are mutations of SARS-CoV-2 that are confirmed to be more infectious, can potentially cause more severe disease, and may be more resistant to existing vaccines compared to the original strain. CoVaRR-Net is working alongside other organizations in Canada and around the world to investigate VOCs and emerging new variants.
There are currently four VOCs in Canada: Alpha (B.1.1.7) (originally detected in the United Kingdom), Beta (B.1.351) (first identified in South Africa), Gamma (P.1) (emerged in Brazil and first reported in Japan), and Delta (B.1.617.2) (first detected in India and is rapidly spreading through the world as the dominant variant).
A variant of interest (VOI) is one that is only “suspected” to either be more contagious than the initial strain, cause more severe disease, or escape the protection offered by vaccines. A VOI can become a VOC if more scientific and clinical evidence emerges that it acquires one or more of these attributes.
The current VOIs in Canada are Lambda (C.37) (first detected in Peru) and Mu (B.1.621) (first detected in Colombia).
A variant under monitoring (VUM), according to the World Health Organization (WHO), is a SARS-CoV-2 variant with genetic changes that are suspected to pose a future risk. It is important to carefully monitor and repeatedly assess VUMs until evidence of their impact is clear.
Simplified SARS-CoV-2 evolutionary tree