By Mariana Bego

The World Health Organization (WHO) has recently announced a new naming system for coronavirus variants using Greek alphabet letters. For example, the B.1.1.7 variant, first identified in the UK, is now designated as “Alpha” and the variant first identified in South Africa, B.1.351, will now be referred to as “Beta.”

 

Most viruses, including SARS-CoV-2, change their genetic programs over time. While the vast majority of changes have little to no impact on the virus’ properties, other changes warrant a more detailed surveillance. These include changes – also known as mutations – that affect the ease at which the virus spreads, disease severity, or vaccine performance. The World Health Organization (WHO) follows the emergence of variants that pose an increased risk to global public health by calling them variants of concern (VOCs) or variants of interest (VOIs).

In a previous summary, we discussed the challenges associated with naming emerging viral variants. Scientists like to use the established naming systems for tracking SARS-CoV-2 genetic lineages (e.g. GISAID, Nextstrain and Pango). However, in order to facilitate public discussions concerning variants, the WHO has recently recommended using Greek Alphabet letters, i.e., Alpha, Beta, Gamma, which may help foster better communication to non-scientific audiences.

 

Based on WHO’s new recommendations, proposed names for the current circulating variants of concern include:

WHO label  Pango  
lineage 
Earliest documented samples  Date of designation 
Alpha  B.1.1.7 United Kingdom,
Sep-2020
18-Dec-2020
Beta  B.1.351 South Africa,
May-2020
18-Dec-2020
Gamma  P.1 Brazil,
Nov-2020
11-Jan-2021
Delta  B.1.617.2 India,
Oct-2020
VOI: 4-Apr-2021
VOC: 11-May-2021

 

The proposed names for current circulating variants of interest include:

WHO label  Pango  
lineage 
Earliest documented samples  Date of designation 
Epsilon   B.1.427/

B.1.429

United States of America,
Mar-2020
5-Mar-2021
Zeta  P.2 Brazil,
Apr-2020
17-Mar-2021
Eta  B.1.525 Multiple countries,
Dec-2020
17-Mar-2021
Theta  P.3 Philippines,
Jan-2021
24-Mar-2021
Iota  B.1.526 United States of America,
Nov-2020
24-Mar-2021
Kappa  B.1.617.1 India,
Oct-2020
4-Apr-2021

 

For additional information, please look at this recent publication in Nature Reviews Microbiology, which summarizes the most relevant mutations in SARS-CoV-2 spike proteins driving these variants.