The World Health Organisation has released a set of labels in Greek alphabet for several variants of SARS-CoV-2 - the coronavirus responsible for the current pandemic.
Ten such letters of the Greek alphabet have been assigned by the WHO - four to variants of concern and six to variants of interest. These letters have been recommended by an expert group of the WHO - to make them easier and more practical to reference by a non-scientific audience.
The first strain to originate in India - first documented in October 2020 - popularly called B.1617.1 (in Pango lineage), has been labelled 'Kappa' by the WHO, which is a variant of interest.
The mutation in it, referred to as B.1617.2, has been labelled 'Delta' by a the WHO, which is a variant of concern.
Here's the letters for each variant.
Variants of interest
Variants of interest is a SARS-CoV-2 isolate whose genome - compared to a reference isolate - has mutated with phenotypic implication. Further, its been shown to have caused transmission or cases, or has been detected in multiple countries. It can also be categorised by the WHO as such.
There are six variants of interest identified by the WHO.
Variants of concern
Such an variant needs to meet the definition of a variant of interest, and has to be associated with the following changes that hold important for global public health:
- Changes in global COVID epidemiology or increased transmissibility
- Increased virulence or differences in presentation
- Decreased effectiveness of health measures against such a variant, such a diagnostics, vaccines or treatment
There are four variants of concern for SARS-CoV-2.
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