SARS-CoV-variants: a guide to detangle the Omicron family name and nomenclature



Every time a new SARS-CoV-2 variant comes into the picture, we all get very confused about its name and nomenclature.

As with several other viruses, the coronavirus SARS-CoV-2 continues to evolve into new variants. However, how sub-variants are named, and how the variants are upgraded to a ‘variant of concern’, etc. seem to be puzzling.

Nature explored some of the pertaining issues like: How do scientists first identify a variant? Why call the Omicron variant circulating here in US the BA.2.12.1? is SARS-CoV-2 evolving more rapidly than other viruses? Could Omicron’s sub-variants, such as BA.4, eventually receive Greek names and more? SARS-CoV-2 acquires mutations as it replicates. Scientists keep looking closely whether the mutations improve the virus’s ability to survive and reproduce or not. Bioinformaticians then compare the viral sequences with hundreds of others using phylogenetic software to look for whether these samples constitute a new branch on the SARS-CoV-2 family tree by using a hierarchical system that indicates the variant’s evolutionary history and relative discovery.


If a variant evades the immune system much more effectively than others and causes more severe disease, WHO might determine it to be a ‘variant of concern’ and change its name to a Greek letter.

Read the full article here.

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