Introduction: The emergence and rapid spread of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a potentially fatal disease, is swiftly leading to public health crises worldwide. The origin of SARS-CoV-2 infection was first reported in people exposed to a seafood market in Wuhan City, China in December 2019.
During the epidemic, the acute respiratory syndrome of coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease, has different strains.
Some types of SARS-CoV-2, which are in the category of variants of interest (VOI) and variants of concern (VOC). Since July 2021, four types of variants of concern (VOC) have emerged and ongoing genomic surveillance is essential for early detection of such variants
Four types of variants of concern (VOC) :
Alpha (B.1.1.7), beta (B.1.351), gamma (P.1) and delta. (B.1.617.2).
Alpha (lineage B.1.1.7):
It was first identified in October 2020 in the United Kingdom during the Covid-19 epidemic in the United Kingdom. The transmission rate of this virus is about 40 to 80% higher than the original virus. The virus has been observed in 12 countries until May 2021.
Beta (lineage B.1.351):
This variant was first observed on December 18, 2020 in South Africa. Unlike the original type of Covid 19, the virus has a high potential for infecting young and healthy people and is more dangerous. Also, several mutations in this virus increase the ability of the virus to attach to human lung cells and increase the ability to spread the virus.
Gamma (lineage P.1):
The gamma type was identified on January 6, 2021 by the Japan National Institute of Infectious Diseases (NIID) in Tokyo. The new species was first identified in four people who left the Brazilian state of Amazonas for Tokyo on January 2, 2021. On January 12, 2021, 13 local gamma-infected individuals were identified in the Amazon rainforest. This type of virus has 17 unique amino acid changes, 10 of which occur in its spike protein.
Delta (lineage B.1.617.2):
Delta was first discovered in India in October 2020 and has since spread internationally.
Five types of variants of interest (VOI):
Eta variant, also known as lineage B.1.525, is SARs-COV-2 virus strain that carries the same E484K-mutation as found in the Gamma, Zeta, and Beta variants. Unlike Alpha, Beta, Gamma, it does not carry the N501Y mutations.
As per reports, this viral strain also carries the same deletion of amino acids histidine and valine in positions 69 and 70, found in Alpha, N439K variant (B.1.141 and B.1.258) and Y453F variant.
Iota (B.1.526):
Iota variant, It was first detected in New York City in November 2020. The variant has appeared with two notable mutations: the E484K spike mutation, which may help the virus evade antibodies, and the S477N mutation, which may help the virus bind more tightly to human cells.
Kappa (B.1.617.1):
Kappa variant was first detected in India in December 2020,The Kappa variant has three notable alterations in the amino-acid sequences, all of which are in the virus's spike protein code.
variant (C.1.2):
cientists in South Africa have discovered a new viral variant of SARS-CoV-2,It’s not a single virus but a clustering of genetically similar viruses, known as C.1.2.
The researchers, in a pre-print study released , found this cluster has picked up a lot of mutations in a short period of time.
SARS-CoV-2 Lambda is now expanding in some South American countries. However, its virological features and evolutionary features remain unknown.
Lambda spike protein is more infectious and is attributed to T76I and L452Q mutations.
This variety has seven unidentified mutations in the Spike gene (Δ247-253, G75V, T76I, L452Q, F490S, T859N) and deletion of the ORF1 gene Δ3675-3677, which neutralizes the antibodies and since the receptor binding domain (RBD) of the SARS protein -CoV-2 S has dominant immunity, mutations in this area can lead to immune escape.
Both classes of variants are concerned with numerous mutations in their spike proteins and are relatively resistant to neutralizing antibodies (NAbs).
In addition, mutations in the N-terminal domain (NTD) of the SARS-CoV-2 S protein are associated with volatile neutralization.
Antibodies that increase viral infection (booster antibodies (EAbs)) have also been detected in severely ill patients, and these EAbs target the N-terminal domain of the NTD.
Methods: This article is a review and does not use laboratory or research methods
Results: This article is a review and does not use laboratory or research methods
Conclusion: SARS COVID- 2 has different variants, which are classified into two categories.
1-variants of concern (VOC) 2- variants of interest (VOI)
Four types of variants of concern :Alpha ,beta, gamma and delta.
Five types of variants of interest (VOI): Eta, Iota , Kappa , variant (C.1.2) and Lambda .
SARS COVID 2 is constantly mutating, and the only way to fight the virus, in addition to following health protocols, is to vaccinate people at high speed around the world, and until the whole world is not vaccinated against the virus, the virus will always mutate. And displays more complex versions of itself.
The main reason for the mutations in this virus is the lack of rapid vaccination of the people of the world, and until the vaccine is distributed evenly and fairly around the world, this problem will exist and we will see the spread of the mutations of this virus.
The lambda spike protein has mutations L452Q and F490S in the RBD, and G75V, T76I mutations and 246-252 deletions in the N-terminal domain (NTD).