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Review
. 2022 Jan 18:11:781429.
doi: 10.3389/fcimb.2021.781429. eCollection 2021.

SARS-COV-2 Variants: Differences and Potential of Immune Evasion

Sandro M Hirabara  1 , Tamires D A Serdan  2 , Renata Gorjao  1 , Laureane N Masi  1 , Tania C Pithon-Curi  1 , Dimas T Covas  3   4 , Rui Curi  1   5 , Edison L Durigon  6   7
Affiliations
Review

SARS-COV-2 Variants: Differences and Potential of Immune Evasion

Sandro M Hirabara et al. Front Cell Infect Microbiol. .

Abstract

The structural spike (S) glycoprotein of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) plays an essential role in infection and is an important target for neutralizing antibody recognition. Mutations in the S gene can generate variants of concern (VOCs), which improve "viral fitness" through selective or survival advantages, such as increased ACE-2 receptor affinity, infectivity, viral replication, higher transmissibility, resistance to neutralizing antibodies and immune escape, increasing disease severity and reinfection risk. Five VOCs have been recognized and include B.1.1.7 (U.K.), B.1.351 (South Africa), P.1 (Brazil), B.1.617.2 (India), and B.1.1.529 (multiple countries). In this review, we addressed the following critical points concerning VOCs: a) characteristics of the SARS-CoV-2 VOCs with mutations in the S gene; b) possible evasion of variants from neutralizing antibodies generated through vaccination, previous infection, or immune therapies; c) potential risk of new pandemic waves induced by the variants worldwide; and d) perspectives for further studies and actions aimed at preventing or reducing the impact of new variants during the current COVID-19 pandemic.

Keywords: COVID-19; delta variant; immune escape; neutralizing antibody; omicron variant; vaccines; variant of concern.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
SARS-CoV-2 structure and mechanisms of infection. ACE-2, angiotensin-converting enzyme-2; E, envelope; M, membrane; N, nucleocapsid; NSP, non-structural protein; S, spike; TMPRSS-2, transmembrane serine protease-2.
Figure 2
Figure 2
Characteristics of key mutations in variants of concern (VOCs). A comparison was performed versus the original virus (WHCV) or the B.1 strain (+D614G). BAA, binding affinity to ACE2; CO, clinical outcome; I, infectivity; IER, immune evasion risk; nAb, neutralizing antibody; SPC, spike protein cleavage; T, transmissibility; VL, viral load; WHCV, WH-Human 1 coronavirus.
Figure 3
Figure 3
Similar and differential mutations in the spike (S) protein from the B.1.1.7, B.1.351, P.1, B.1.617, and B.1.1.529 variants of concern. NTD, N terminal domain; RBD, receptor-binding domain.
Figure 4
Figure 4
Distribution of the SARS-CoV-2 variants of concern in several countries. Data were analyzed from GISAID from September 2020 to November 2021 (https://www.gisaid.org/hcov19-variants/).
See this image and copyright information in PMC

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