SARS-CoV-2 Variants List: How many variants of COVID-19 are there in the world?

SARS-CoV-2 Variants List: First detected in China's Wuhan in 2019, SARS-CoV-2 has undergone many mutations. While some have the potential to increase transmissibility and virulence, others may reduce the effectiveness of vaccines against them.

Three months ago, the XE variant of COVID-19 was reported in the United Kingdom. It is recombinant as it contains the mutations found in BA.1 and BA.2 which are sub-variants of Omicron. 

Omicron had been declared as a Variant of Concern by WHO in November 2021. The latest strain of SARS-CoV-2 was discovered in South Africa and is said to be more dangerous than the Delta variant. 

Through this article, let us have a look at the most notable variants of SARS-COV-2, the virus that causes COVID-19. 

Variants of Concern (VOC)

Variants of Concern (VOC) are those variants that increase virus characteristics such as transmissibility and virulence, with a significant decrease in the effectiveness of available diagnostics, vaccines, and therapeutics.

Alpha Variant (lineage B.1.1.7)

Lineage B.1.1.7 of SARS-CoV-2 was first reported in the United Kingdom in September 2020. It is also known as 20I/501Y.V1 or 501Y.V1. On 18 December 2020, WHO declared it as a Variant of Concern (VOC). In their recent research, scientists have found no evidence of increased virulence. As of May 2021, the variant has been detected in around 120 countries. On 31 May 2021, WHO named it Alpha. 

Alpha Variant with E484K

On 2 February 2021, Public Health England reported the detection of a limited number of B.1.1.7 with E484K mutations, which they dubbed Variant of Concern 202102/02 (VOC-202102/02). Other names for this variant include B.1.1.7+E484K and B.1.1.7 Lineage with S: E484K. One of the mutations (N501Y) is also present in the Beta variant and Gamma variant.

Beta Variant (lineage B.1.351)

Lineage B.1.351 of  SARS-CoV-2 was first reported in South Africa in May 2020. It is also known as 501.V2, 20H/501Y.V2 or 501Y.V2. Its prevalence is higher among young people with no underlying health conditions and is more frequently resulting in serious illness in comparison with other variants. On 18 December 2020, WHO declared it a Variant of Concern (VOC). On 31 May 2021, WHO named it Beta. 

Gamma Variant (lineage P.1)

Lineage P.1  of  SARS-CoV-2 was first reported in Brazil in November 2020. It is a descendent of lineage B.1.1.28. It has 17 unique amino acid changes, 10 of which are in its spike protein, including the three concerning mutations: N501Y, E484K and K417T. It showed 2.2 times higher transmissibility with the same ability to infect both adults and elderly people. On 11 January 2021, WHO declared it a Variant of Concern (VOC). On 31 May 2021, WHO named it Gamma. 

Delta Variant (lineage B.1.617.2)

Lineage B.1.617.2 of SARS-CoV-2 was first reported in India in October 2020. On 11 May 2021, WHO declared it as a Variant of Concern (VOC) and named it Delta on 31 May 2021. It can spread almost twice as fast as the Alpha variant and carries L452R, T478K and P681R mutations. The highly transmissible Delta variant has mutated further to form the 'Delta plus' or 'AY.1' variant. However, the newly-added variant is not yet a 'variant of concern' as its incidence is still low in India.

Omicron Variant (lineage B.1.1.529 )

The lineage of B.1.1.529 was first reported in South Africa in November 2021. WHO designated it as a Variant of Concern (VOC) on 26 November 2021 and named it Omicron. The latest variant of SARS-CoV-2 is said to be more dangerous than the previous variant of COVID-19, i.e. Delta variant. Omicron is contagious-- can spread quickly-- and is not resistant to the current vaccine. 

Variants of Interest (VOI)

Variants of Interest (VOI) are those variants that are predicted to affect virus characteristics such as transmissibility, disease severity, immune escape, and diagnostic or therapeutic escape. Furthermore, these may cause significant community transmission, thereby posing a greater risk to public health globally. 

Epsilon Variant (lineages  B.1.429, B.1.427)

Lineage B.1.429, B.1.427 of SARS-CoV-2 was first reported in the United States in March 2020. It is defined by five distinct mutations-- I4205V and D1183Y in the ORF1ab-gene, and S13I, W152C, L452R in the spike protein's S-gene. On 5 March 2021, WHO designated it as a Variant of Interest (VOI) and named it Epsilon on 31 May 2021.

Eta Variant (lineage B.1.525)

Lineage B.1.525 of SARS-CoV-2 was reported in multiple countries in December 2020. Public Health England designated it as a Variant Under Investigation (VUI-21FEB-03). Eta differs from all other variants as it has both the E484K-mutation and a new F888L mutation. On 17 March 2021, WHO designated it as a Variant of Interest (VOI) and named it Eta on 31 May 2021.

Kappa Variant (lineage B.1.617.1)

Lineage B.1.617.1 of SARS-CoV-2 was first reported in India in December 2020. On 1 April 2021, Public Health England designated it as a Variant Under Investigation (VUI-21APR-01). On 4 April 2021, WHO designated it as a Variant of Interest (VOI) and named it Kappa on 31 May 2021.

Both Delta and Kappa are the sublineages of lineage B.1.617. 

Lambda Variant (lineage C.37)

Lineage C.37 of SARS-CoV-2 was first reported in Peru in August 2020. It carries mutations that might increase transmissibility or strengthen the virus's resistance to antibodies. On 14 June 2021, WHO designated it as a Variant of Interest (VOI) and named it Lambda on 31 May 2021.

Lota Variant (lineage B.1.526)

Lineage B.1.526 of SARS-CoV-2 was first reported in the United States in November 2020. Initially, it reached relatively high levels in some regions but was outcompeted by the more transmissible Alpha variant in the spring of 2021. On 24 March 2021, WHO designated it as a Variant of Interest (VOI) and named it Lota on 31 May 2021.

Theta Variant (lineage P.3)

Lineage P.3 of SARS-CoV-2 was first reported in the Philippines in January 2021. On 24 March 2021, WHO designated it as a Variant of Interest (VOI) and named it Theta on 31 May 2021.

Zeta Variant (lineage P.2)

Lineage P.2 of SARS-CoV-2 was first reported in Brazil in April 2020. On 17 March 2021, WHO designated it as a Variant of Interest (VOI) and named it Zeta on 31 May 2021.

Mu Variant (B.1.621)

Lineage B.1.621 of SARS-CoV-2 was first observed in January 2021 in Colombia. The World Health Organization designated it as a Variant of Interest (VOI) and named it Mu on 30 August 2021.

Variants Under Monitoring (VUM)

Variants Under Monitoring (VUM) are those variants that have genetic changes and may affect virus characteristics in such a way that could pose a future risk, but evidence of their epidemiological impact is unclear, and thus require enhanced monitoring. 

How are the Coronavirus variants named?