https://doi.org/10.4081/monaldi.2022.2337
SARS-CoV-2 variants of concern: a review
Submitted: May 22, 2022
Accepted: October 17, 2022
Published: October 25, 2022
Accepted: October 17, 2022
Abstract Views: 1821
PDF: 940
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All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Authors
The virus that causes severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the genus Beta coronavirus and the family Coronaviridae. The SARS-CoV-2 virus is a positive sense, non-segmented single-strand RNA virus that causes coronavirus disease 2019 (COVID-19), which was first reported in December 2019 in Wuhan, China. COVID-19 is now a worldwide pandemic. Globally, several newer variants have been identified; however, only a few of them are of concern (VOCs). VOCs differ in terms of infectivity, transmissibility, disease severity, drug efficacy, and neutralization efficacy by monoclonal antibodies, convalescent sera, or vaccines. VOCs reported from various parts of the world include B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617/B.1.617.2 (Delta), P.1 (Gamma), and B.1.1.529 (Omicron). These VOCs are the result of mutations, with some based on spike proteins. Mutations may also cause molecular diagnostic tests to fail to detect the few VOCs, leading to a delayed diagnosis, increased community spread, and delayed treatment. We searched PubMed, EMBASE, Covariant, Stanford variants database, and CINAHL from December 2019 to February 2022 using the following search terms: Variant of Concern, SARS-CoV-2, Omicron, etc. All types of research were chosen. All research methods were considered. This review discusses the various VOCs, as well as their mutations, infectivity, transmissibility, and neutralization efficacy.
Cui J, Li F, Shi ZL. Origin and evolution of pathogenic coronaviruses. Nat Rev Microbiol 2019;17:181-92.
DOI: https://doi.org/10.1038/s41579-018-0118-9
Jackson CB, Farzan M, Chen B, Choe H. Mechanisms of SARS-CoV-2 entry into cells. Nat Rev Mol Cell Biol 2022;23:3-20.
DOI: https://doi.org/10.1038/s41580-021-00418-x
Hoffmann M, Kleine-Weber H, Schroeder S, et al. SARS-CoV-2 cell entry depends on ACE2 and TMPRSS2 and is blocked by a clinically proven protease inhibitor. Cell 2020;181:271-80.
DOI: https://doi.org/10.1016/j.cell.2020.02.052
Yang N, Shen HM. Targeting the endocytic pathway and autophagy process as a novel therapeutic strategy in COVID-19. Int J Biol Sci 2020;16:1724-31.
DOI: https://doi.org/10.7150/ijbs.45498
Kawase M, Shirato K, van der Hoek L, et al. Simultaneous treatment of human bronchial epithelial cells with serine and cysteine protease inhibitors prevents severe acute respiratory syndrome coronavirus entry. J Virol 2012;86:6537-45.
DOI: https://doi.org/10.1128/JVI.00094-12
Chen Y, Liu Q, Guo D. Emerging coronaviruses: genome structure, replication, and pathogenesis. J Med Virol 2020;92:418-23.
DOI: https://doi.org/10.1002/jmv.25681
Moeller NH, Shi K, Demir Ö, et al. Structure and dynamics of SARS-CoV-2 proofreading exoribonuclease ExoN. Proc Natl Acad Sci USA 2022;119:e2106379119.
DOI: https://doi.org/10.1073/pnas.2106379119
Robson F, Khan KS, Le TK, et al. Coronavirus RNA proofreading: Molecular basis and therapeutic targeting. Mol Cell 2020;79:710-27.
DOI: https://doi.org/10.1016/j.molcel.2020.07.027
Denison MR, Graham RL, Donaldson EF, et al. Coronaviruses: an RNA proofreading machine regulates replication fidelity and diversity. RNA Biol. 2011;8:270-9.
DOI: https://doi.org/10.4161/rna.8.2.15013
Zhou P, Yang X-L, Wang X-G, et al. A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature 2020;579:270-3.
DOI: https://doi.org/10.1038/s41586-020-2012-7
World Health Organization. Tracking SARS-CoV-2 variants. Accessed on: 25 June 2021. Available from: https://www.who.int/en/activities/tracking-SARS-CoV-2-variants/
Srivastava S, Banu S, Singh P, et al. SARS-CoV-2 genomics: An Indian perspective on sequencing viral variants. J Biosci 2021;46:22.
DOI: https://doi.org/10.1007/s12038-021-00145-7
Centers for Disease Control and Prevention. SARS-CoV-2 variant classifications and definitions. Accessed on: 25 June 2021. Available from: https://www.cdc.gov/coronavirus/2019-ncov/variants/variant-info.html
Callaway E. The coronavirus is mutating - does it matter? Nature 2020;585:174-7.
DOI: https://doi.org/10.1038/d41586-020-02544-6
American Society for Microbiology. Biography Ashley Hagen, M.S. Science Communications Specialist. Accessed on: 25 June 2021. Available from: https://asm.org/Biographies/Ashley-Hagen
Cella E, Benedetti F, Fabris S, et al. SARS-CoV-2 Lineages and sub-lineages circulating worldwide: A dynamic overview. Chemotherapy 2021;66:3-7.
DOI: https://doi.org/10.1159/000515340
World Health Organization. Global consultation on a decision framework for assessing the impact of SARS-CoV-2 variants of concern on public health interventions. Accessed on: 1 December 2021. Available from: https://www.who.int/news-room/events/detail/2021/03/29/default-calendar/global-consultation-on-a-decision-framework-for-assessing-the-impact-of-sars-cov-2-variants-of-concern-on-public-health-interventions
Davies NG, Abbott S, Barnard RC, et al. Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England. Science 2021;372:6538.
DOI: https://doi.org/10.1126/science.abg3055
European Centre for Disease Prevention and Control. Rapid increase of a SARS-CoV-2 variant with multiple spike protein mutations observed in the United Kingdom, December 2020. Accessed on: 1 December 2021. Available from: https://www.ecdc.europa.eu/sites/default/files/documents/SARS-CoV-2-variant-multiple-spike-protein-mutations-United-Kingdom.pdf
Horby P, Huntley C, Davies N, et al. NERVTAG note on B.1.1.7 severity. Available from: https://depts.washington.edu/pandemicalliance/2021/01/25/nervtag-note-on-b-1-1-7-severity/
Volz E, Mishra S, Chand M, et al. Assessing transmissibility of SARS-CoV-2 lineage B.1.1.7 in England. Nature 2021;593:266-9.
DOI: https://doi.org/10.1038/s41586-021-03470-x
Li R, Liu J, Zhang H. The challenge of emerging SARS-CoV-2 mutants to vaccine development. J Genet Genomics 2021;48:102-6.
DOI: https://doi.org/10.1016/j.jgg.2021.03.001
Davies NG, Jarvis CI, CMMID COVID-19 Working Group, et al. Increased mortality in community-tested cases of SARS-CoV-2 lineage B.1.1.7. Nature 2021;593:270–4.
DOI: https://doi.org/10.1038/s41586-021-03426-1
Shen X, Tang H, McDanal C, et al. SARS-CoV-2 variant B.1.1.7 is susceptible to neutralizing antibodies elicited by ancestral spike vaccines. Cell Host Microbe 2021;29:529-39.e3.
DOI: https://doi.org/10.1016/j.chom.2021.03.002
Liu H, Zhang Q, Wei P, et al. The basis of a more contagious 501Y.V1 variant of SARS-COV-2. Cell Res 2021;31:720-2.
DOI: https://doi.org/10.1038/s41422-021-00496-8
Wang P, Nair MS, Liu L, et al. Antibody resistance of SARS-CoV-2 variants B.1.351 and B.1.1.7. Nature 2021;593:130-5.
DOI: https://doi.org/10.1038/s41586-021-03398-2
Santos JC, Passos GA. The high infectivity of SARS-CoV-2 B.1.1.7 is associated with increased interaction force between spike-ACE2 caused by the viral N501Y mutation. bioRxiv 2020.12.29.424708.
DOI: https://doi.org/10.1101/2020.12.29.424708
Gupta RK. Will SARS-CoV-2 variants of concern affect the promise of vaccines? Nat Rev Immunol 2021;21:340-1.
DOI: https://doi.org/10.1038/s41577-021-00556-5
Thakur V, Bhola S, Thakur P, et al. Waves and variants of SARS-CoV-2: understanding the causes and effect of the COVID-19 catastrophe. Infection 2022;50:309-25.
DOI: https://doi.org/10.1007/s15010-021-01734-2
Mccarthy KR, Rennick LJ, Nambulli S, et al. Natural deletions in the SARS-CoV-2 spike glycoprotein drive antibody escape. Science 2021;371:1139-42.
DOI: https://doi.org/10.1126/science.abf6950
Otto SP, Day T, Arino J, et al. The origins and potential future of SARS-CoV-2 variants of concern in the evolving COVID-19 pandemic. Curr Biol 2021;31:R918-29.
DOI: https://doi.org/10.1016/j.cub.2021.06.049
Rees-Spear C, Muir L, Griffith SA, et al. The effect of spike mutations on SARS-CoV-2 neutralization. Cell Rep 2021;34:108890.
DOI: https://doi.org/10.1016/j.celrep.2021.108890
US Food and Drug Administration. Fact sheet for health care providers emergency use authorization (EUA) of bamlanivimab and etesevimab. Accessed on: 21 December 2021 Available from: https://www.fda.gov/media/145802/download
US Food and Drug Administration. Fact sheet for health care providers emergency use authorization (EUA) of REGEN-COV (casirivimab with imdevimab). Accessed on: 21 December 2021 Available from: https://www.fda.gov/media/145611/download
US Food and Drug Administration. Fact sheet for health care providers emergency use authorization (EUA) of sotrovimab. Accessed on: 21 December 2021 Available from: https://www.fda.gov/media/149534/download
Collier DA, De Marco A, Ferreira IATM, et al. Sensitivity of SARS-CoV-2 B.1.1.7 to mRNA vaccine-elicited antibodies. Nature 2021;593:136-41.
DOI: https://doi.org/10.1038/s41586-021-03412-7
Andreano E, Piccini G, Licastro D, et al. SARS-CoV-2 escape in vitro from a highly neutralizing COVID-19 convalescent plasma. Proc Natl Acad Sci USA 2021;118:e2103154118.
DOI: https://doi.org/10.1073/pnas.2103154118
Tegally H, Wilkinson E, Giovanetti M, et al. Detection of a SARS-CoV-2 variant of concern in South Africa. Nature 2021;592:438-43.
DOI: https://doi.org/10.1038/s41586-021-03402-9
Dubey A, Choudhary S, Kumar P, Tomar S. Emerging SARS-CoV-2 variants: Genetic variability and clinical implications. Curr Microbiol 2021;79:20.
DOI: https://doi.org/10.1007/s00284-021-02724-1
Chakraborty C, Bhattacharya M, Sharma AR. Present variants of concern and variants of interest of severe acute respiratory syndrome coronavirus 2: Their significant mutations in S-glycoprotein, infectivity, re-infectivity, immune escape and vaccines activity. Rev Med Virol 2021;32:e2270.
DOI: https://doi.org/10.1002/rmv.2270
UpToDate [Internet]. COVID-19: Epidemiology, virology, and prevention. Accessed on 11 May 2022. Available from: https://www.uptodate.com/contents/covid-19-epidemiology-virology-and-prevention
Cele S, Gazy I, Jackson L, et al. Escape of SARS-CoV-2 501Y.V2 from neutralization by convalescent plasma. Nature 2021;593:142-6.
DOI: https://doi.org/10.1038/s41586-021-03471-w
Wise J. Covid-19: The E484K mutation and the risks it poses. BMJ 2021;372 n359.
DOI: https://doi.org/10.1136/bmj.n359
Wibmer CK, Ayres F, Hermanus T, et al. SARS-CoV-2 501Y.V2 escapes neutralization by South African COVID-19 donor plasma. Nat Med 2021;27:622-5.
DOI: https://doi.org/10.1038/s41591-021-01285-x
Butt AA, Dargham SR, Chemaitelly H, et al. Severity of illness in persons infected with the SARS-CoV-2 delta variant vs beta variant in Qatar. JAMA Intern Med 2022;182:197-205.
DOI: https://doi.org/10.1001/jamainternmed.2021.7949
Faria NR, Mellan TA, Whittaker C, et al. Genomics and epidemiology of the P.1 SARS-CoV-2 lineage in Manaus, Brazil. Science 2021;372:815-21.
DOI: https://doi.org/10.1126/science.abh2644
Jhun H, Park HY, Hisham Y, et al. SARS-CoV-2 Delta (B.1.617.2) variant: A unique T478K mutation in receptor binding motif (RBM) Spike gene. Immune Netw 2021;21:e32.
DOI: https://doi.org/10.4110/in.2021.21.e32
Wang P, Casner RG, Nair MS, et al. Increased resistance of SARS-CoV-2 variant P.1 to antibody neutralization. Cell Host Microbe. 2021;29:747-51.
DOI: https://doi.org/10.1016/j.chom.2021.04.007
Wang R, Zhang Q, Ge J, et al. Analysis of SARS-CoV-2 variant mutations reveals neutralization escape mechanisms and the ability to use ACE2 receptors from additional species. Immunity 2021;54:1611-21.
DOI: https://doi.org/10.1016/j.immuni.2021.06.003
Public Health England. SARS-CoV-2 variants of concern and variants under investigation in England. Technical briefing 14. June 3, 2021. Accessed on 25 December 2021. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/991343/Variants_of_Concern_VOC_Technical_Briefing_14.pdf
Lopez Bernal J, Andrews N, Gower C, et al. Effectiveness of Covid-19v against the B.1.617.2 (Delta) variant. N Engl J Med 2021;385:585-94.
DOI: https://doi.org/10.1056/NEJMoa2108891
Public Health England. COVID-19 vaccine surveillance report: Week 29. Accessed on 25 December 2021. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1005085/Vaccine_surveillance_report_-_week_29.pdf
Nasreen S, Chung H, He S, et al. Effectiveness of COVID-19 vaccines against symptomatic SARS-CoV-2 infection and severe outcomes with variants of concern in Ontario. Nat Microbiol 2022;7:379-85.
DOI: https://doi.org/10.1038/s41564-021-01053-0
American Society for Microbiology. How dangerous Is the Delta variant (B.1.617.2)? Accessed on 5 December 2021. Available from: https://asm.org/Articles/2021/July/How-Dangerous-is-the-Delta-Variant-B-1-617-2
Li B, Deng A, Li K, et al iral infection and transmission in a large, well-traced outbreak caused by the SARS-CoV-2 Delta variant. Nat Commun 2022;13:460.
Sheikh A, McMenamin J, Taylor B, et al. SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospital admission, and vaccine effectiveness. Lancet 2021;397:2461-2.
DOI: https://doi.org/10.1016/S0140-6736(21)01358-1
Public Health England. 3 June 2021 Risk assessment for SARS-CoV-2 variant: Delta (VOC-21APR-02, B.1.617.2). Accessed on 25 December 2021. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/991135/3_June_2021_Risk_assessment_for_SARS-CoV-2_variant_DELTA.pdf
Twohig KA, Nyberg T, Zaidi A, et al. Hospital admission and emergency care attendance risk for SARS-CoV-2 delta (B.1.617.2) compared with (B.1.1.7) variants of concern: a cohort study. Lancet Infect Dis 2022;22:35-42.
DOI: https://doi.org/10.1016/S1473-3099(21)00475-8
Cherian S, Potdar V, Jadhav S, et al. SARS-CoV-2 Spike mutations, L452R, T478K, E484Q and P681R, in the second wave of COVID-19 in Maharashtra, India. Microorganisms 2021;9:1542.
DOI: https://doi.org/10.3390/microorganisms9071542
Rahman FI, Ether SA, Islam MR. The "Delta Plus" COVID-19 variant has evolved to become the next potential variant of concern: mutation history and measures of prevention. J Basic Clin Physiol Pharmacol 2021;33:109-12.
DOI: https://doi.org/10.1515/jbcpp-2021-0251
Yadav PD, Sapkal GN, Abraham P, et al. Neutralization of variant under investigation B.1.617.1 with sera of BBV152 vaccinees. Clin Infect Dis 2022;74:366-8.
DOI: https://doi.org/10.1093/cid/ciab411
Roy, B, Roy, H. The Delta Plus variant of COVID-19: will it be the worst nightmare in the SARS-CoV-2 pandemic? J Biomed Sci 2021;8:1-2.
DOI: https://doi.org/10.3126/jbs.v8i1.38449
Arora P, Kempf A, Nehlmeier I, et al. Delta variant (B.1.617.2) sub lineages do not show increased neutralization resistance. Cell Mol Immunol 2021;18:2557-9.
DOI: https://doi.org/10.1038/s41423-021-00772-y
Kannan SR, Spratt AN, Cohen AR, et al. Evolutionary analysis of the Delta and Delta Plus variants of the SARS-CoV-2 viruses. J Autoimmun 2021;124:102715.
DOI: https://doi.org/10.1016/j.jaut.2021.102715
Science [Internet]. Delta variant triggers dangerous new phase in the pandemic. Availblae from: https://www.science.org/content/article/delta-variant-triggers-dangerous-new-phase-pandemic#:~:text=When%20the%20coronavirus%20variant%20now,reported%20daily%20in%20late%20April
Saito A, Irie T, Suzuki R, et al. Enhanced fusogenicity and pathogenicity of SARS-CoV-2 Delta P681R mutation. Nature 2022;602:300-6.
DOI: https://doi.org/10.1038/s41586-021-04266-9
World Health Organization. Update on omicron. 2021. Accessed on 29 December 2021. Available from: https://www.who.int/news/item/28-11-2021-update-on-omicron
Garcia-Beltran WF, St Denis KJ, Hoelzemer A, et al. mRNA-based COVID-19 vaccine boosters induce neutralizing immunity against SARS-CoV-2 Omicron variant. Cell 2022;185:457-66.
DOI: https://doi.org/10.1016/j.cell.2021.12.033
Torjesen I. Covid-19: Omicron may be more transmissible than other variants and partly resistant to existing vaccines, scientists fear. BMJ 2021;375:n2943.
DOI: https://doi.org/10.1136/bmj.n2943
Flemming A. Omicron, the great escape artist. Nat Rev Immunol 2022;22:75.
DOI: https://doi.org/10.1038/s41577-022-00676-6
Kannan SR, Spratt AN, Sharma K, et al. Omicron SARS-CoV-2 variant: Unique features and their impact on pre-existing antibodies. J Autoimmun 2022;126:102779.
DOI: https://doi.org/10.1016/j.jaut.2021.102779
Gong SY, Chatterjee D, Richard J, et al. Contribution of single mutations to selected SARS-CoV-2 emerging variants spike antigenicity. Virology 2021;563:134-45.
DOI: https://doi.org/10.1016/j.virol.2021.09.001
Zhang L, Mann M, Syed ZA, et al. Furin cleavage of the SARS-CoV-2 spike is modulated by O-glycosylation. Proc Natl Acad Sci USA 2021;118:e2109905118.
DOI: https://doi.org/10.1073/pnas.2109905118
Chen J, Wang R, Gilby NB, Wei GW. Omicron variant (B.1.1.529): Infectivity, vaccine breakthrough, and antibody resistance. J Chem Inf Model 2022;62:412-42.
DOI: https://doi.org/10.1021/acs.jcim.1c01451
Pulliam JRC, van Schalkwyk C, Govender N, et al. Increased risk of SARS-CoV-2 reinfection associated with emergence of Omicron in South Africa. Science 2022;376:eabn4947.
DOI: https://doi.org/10.1126/science.abn4947
Liu C, Ginn HM, Dejnirattisai W, et al. Reduced neutralization of SARS-CoV-2 B.1.617 by vaccine and convalescent serum. Cell 2021;184:4220-36.
DOI: https://doi.org/10.1016/j.cell.2021.06.020
Garcia-Beltran WF, Lam EC, St Denis K, et al. Multiple SARS-CoV-2 variants escape neutralization by vaccine-induced humoral immunity. Cell 2021;184:2372-83.
DOI: https://doi.org/10.1016/j.cell.2021.03.013
He X, Hong W, Pan X, et al. SARS-CoV-2 Omicron variant: Characteristics and prevention. Med Comm (2020) 2021;2:838-45.
DOI: https://doi.org/10.1002/mco2.110
Quarleri J, Galvan V, Delpino MV. Omicron variant of the SARS-CoV-2: a quest to define the consequences of its high mutational load. Geoscience 2022;44:53-6.
DOI: https://doi.org/10.1007/s11357-021-00500-4
SAMRC [Internet]. Tshwane District Omicron variant patient profile-early features. Available from: https://www.samrc.ac.za/news/tshwane-district-omicron-variant-patient-profile-early-features
Kumar S, Thambiraja TS, Karuppanan K, Subramaniam G. Omicron and Delta variant of SARS-CoV-2: A comparative computational study of spike protein. J Med Virol 2022;94:1641-9.
DOI: https://doi.org/10.1002/jmv.27526
Chi X, Yan R, Zhang J, et al. A neutralizing human antibody binds to the N-terminal domain of the Spike protein of SARS-CoV-2. Science 2020;369:650-5.
DOI: https://doi.org/10.1126/science.abc6952
Dejnirattisai W, Zhou D, Supasa P, et al. Antibody evasion by the P.1 strain of SARS-CoV-2. Cell 2021;184:2939-54.
DOI: https://doi.org/10.1016/j.cell.2021.03.055
Liu L, Iketani S, Guo Y, et al. Striking antibody evasion manifested by the Omicron variant of SARS-CoV-2. Nature 2022;602:676-81.
DOI: https://doi.org/10.1038/s41586-021-04388-0
Hoffmann M, Krüger N, Schulz S, et al. The Omicron variant is highly resistant against antibody-mediated neutralization: Implications for control of the COVID-19 pandemic. Cell 2021;185:447-56.
DOI: https://doi.org/10.1016/j.cell.2021.12.032
Gupta A, Gonzalez-Rojas Y, Juarez E, et al. Early treatment for Covid-19 with SARS-CoV-2 neutralizing antibody sotrovimab. N Engl J Med 2021;385:1941-50.
DOI: https://doi.org/10.1056/NEJMoa2107934
Planas D, Saunders N, Maes P, et al. Considerable escape of SARS-CoV-2 Omicron to antibody neutralization. Nature 2021;602:671-5.
DOI: https://doi.org/10.1038/s41586-021-04389-z
Ferré VM, Peiffer-Smadja N, Visseaux B, et al. Omicron SARS-CoV-2 variant: What we know and what we don't. Anaesth Crit Care Pain Med. 2021;41:100998.
DOI: https://doi.org/10.1016/j.accpm.2021.100998
World Health Organization. Enhancing Readiness for Omicron (B.1.1.529): Technical Brief and Priority Actions for Member States. December 10, 2021. Accessed on December 13, 2021. Available from: https://www.who.int/docs/default-source/coronaviruse/2021-12-23-global-technical-brief-and-priority-action-on-omicron.pdf?sfvrsn=d0e9fb6c_8
Grabowski F, Kochańczyk M, Lipniacki T. Omicron strain spreads with the doubling time of 3.2-3.6 days in South Africa province of Gauteng that achieved herd immunity to Delta variant. medRxiv 2021.12.08.2126749.
Imperial College London. Report 49 - Growth, population distribution and immune escape of the Omicron in England. 2021. Accessed on 13 December 2021. Available from: https://www.imperial.ac.uk/mrc-global-infectious-disease-analysis/covid-19/report-49-omicron/
Pearson C, Silal S, Li M, et al. Bounding the levels of transmissibility & immune evasion of the Omicron variant in South Africa. medRxiv 2021.12.19.21268038.
DOI: https://doi.org/10.1101/2021.12.19.21268038
UK Health Security Agency. Investigation of SARS-CoV-2 variants of concern: technical briefings. 2021. Accessed on 23 December 2021. Available from: https://www.gov.uk/government/publications/investigation-of-novel-sars-cov-2-variant-variant-of-concern-20201201
Wolter N, Jassat W, Walaza S, et al. Early assessment of the clinical severity of the SARS-CoV-2 omicron variant in South Africa: a data linkage study. Lancet 2022;399:437-4.
DOI: https://doi.org/10.1016/S0140-6736(22)00017-4
Imperial College London. Hospitalisation risk for Omicron cases in England. 2021. Accessed on 30 December 2021. Available from: https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2021-12-22-COVID19-Report-50.pdf
Sheikh A, Kerr S, Woolhouse M, et al. Severity of Omicron variant of concern and vaccine effectiveness against symptomatic disease: national cohort with nested test negative design study in Scotland. 2021. Accessed on 30 December 2021. Available from: https://politi.co/3EqDs2y
Espenhain L, Funk T, Overvad M, et al. Epidemiological characterisation of the first 785 SARS-CoV-2 Omicron variant cases in Denmark, December 2021. Euro Surveill 2021;26:2101146.
DOI: https://doi.org/10.2807/1560-7917.ES.2021.26.50.2101146
Public Health Ontario. Early estimates of Omicron severity in Ontario based on a matched cohort study, November 22 to December 17, 2021. Toronto, ON: Queen’s Printer for Ontario; 2021. Accessed on 30 December 2021. Available from: https://www.publichealthontario.ca/-/media/documents/ncov/epi/covid-19-epi-enhanced-estimates-omicron-severity-study.pdf?sc_lang=en
Abdullah F, Myers J, Basu D, et al. Decreased severity of disease during the first global omicron variant covid-19 outbreak in a large hospital in Tshwane, South Africa. Int J Infect Dis 2021;116:38-42.
DOI: https://doi.org/10.1016/j.ijid.2021.12.357
Maslo C, Friedland R, Toubkin M, et al. Characteristics and outcomes of hospitalized patients in South Africa during the COVID-19 Omicron wave compared with previous waves. JAMA 2022;327:58384.
DOI: https://doi.org/10.1001/jama.2021.24868
U.K. health Security Agency. SARS-CoV-2 variants of concern and variants under investigation in England. Accessed on 3 January 2022. Available from: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1045619/Technical-Briefing-31-Dec-2021-Omicron_severity_update.pdf
McMahan K, Giffin V, Tostanoski LH, et al. Reduced pathogenicity of the SARS-CoV-2 omicron variant in hamsters. Med (N Y) 2022;3:262–8.
DOI: https://doi.org/10.1016/j.medj.2022.03.004
World Health Organization. Weekly epidemiological update on COVID-19. June 1, 2022. Available from: https://www.who.int/publications/m/item/weekly-epidemiological-update-on-covid-19---1-june-2022
Mahase E. Omicron sub-lineage BA.2 may have "substantial growth advantage," UKHSA reports. BMJ 2022;376:o263.
DOI: https://doi.org/10.1136/bmj.o263
Majumdar S, Sarkar R. Mutational and phylogenetic analyses of the two lineages of the Omicron variant. J Med Virol 2022;94:1777-9.
DOI: https://doi.org/10.1002/jmv.27558
Khan K, Karim F, Cele S, et al. Omicron infection enhances neutralizing immunity against the Delta variant. Nature 2022;607:356–9.
DOI: https://doi.org/10.1101/2021.12.27.21268439
US Food and Drug Administration. Fact sheet for health care providers emergency use authorization (EUA) of bebtelovimab. Available from: https://www.fda.gov/media/156152/download
US Food and Drug Administration. Fact sheet for health care providers emergency use authorization (EUA) of tixagevimab co-packaged with cilgavimab. Available from: https://www.fda.gov/media/154701/download
Takashita E, Kinoshita N, Yamayoshi S, et al. Efficacy of antiviral agents against the SARS-CoV-2 omicron subvariant BA.2. N Engl J Med 2022;386:1475.
DOI: https://doi.org/10.1056/NEJMc2201933
Takashita E, Yamayoshi S, Simon V, et al. Efficacy of antibodies and antiviral drugs against omicron BA.2.12.1, BA.4, and BA.5 subvariants. N Engl J Med 2022;387:468-70.
DOI: https://doi.org/10.1056/NEJMc2207519
The Guardian [Internet]. Centaurus’: virologists express concern at new Covid subvariant. Available from: https://www.theguardian.com/world/2022/jul/12/centaurus-virologists-express-concern-at-new-covid-subvariant-omicron
DNA India [Internet]. Covid 4th wave: Know all about spread, symptoms of Centaurus variant of Omicron, how it was named. Available from: https://www.dnaindia.com/health/report-covid-4th-wave-know-all-about-spread-symptoms-of-centaurus-variant-of-omicron-how-it-was-named-2969982
Iketani S, Liu L, Guo Y, et al. Antibody evasion properties of SARS-CoV-2 Omicron sublineages. Nature 2022;604:553-56.
DOI: https://doi.org/10.1038/s41586-022-04594-4
Stanford University. Omicron BA.1. Accessed on 24 July 2022. Available from: https://covdb.stanford.edu/variants/omicron/
Emary KRW, Golubchik T, Aley PK, et al. Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 variant of concern 202012/01 (B.1.1.7): an exploratory analysis of a randomized controlled trial. Lancet 2021;397:1351-62.
DOI: https://doi.org/10.1016/S0140-6736(21)00628-0
Abu-Raddad LJ, Chemaitelly H, Butt AA, National Study Group for COVID-19 Vaccination. Effectiveness of the BNT162b2 Covid-19 Vaccine against the B.1.1.7 and B.1.351 Variants. N Engl J Med 2021;385:187-9.
DOI: https://doi.org/10.1056/NEJMc2104974
Bruxvoort KJ, Sy LS, Qian L, et al. Effectiveness of mRNA-1273 against delta, mu, and other emerging variants of SARS-CoV-2: test negative case-control study. BMJ 2021;375:e068848.
DOI: https://doi.org/10.1136/bmj-2021-068848
CBS News [Internet]. Gottlieb says Delta virus variant likely to become dominant U.S. strain. Accessed on 1 January 2022. Available from: https://www.cbsnews.com/news/covid-19-delta-varient-dominant-strain-likely/
Shinde V, Bhikha S, Hoosain Z, et al. Efficacy of NVX-CoV2373 Covid-19 vaccine against the B.1.351 variant. N Engl J Med 2021;384:1899-909.
DOI: https://doi.org/10.1056/NEJMoa2103055
Chemaitelly H, Yassine HM, Benslimane FM, et al. mRNA-1273 COVID-19 vaccine effectiveness against the B.1.1.7 and B.1.351 variants and severe COVID-19 disease in Qatar. Nat Med 2021;27:1614-21.
DOI: https://doi.org/10.1038/s41591-021-01446-y
Sadoff J, Gray G, Vandebosch A, et al. Safety and efficacy of single-dose Ad26.COV2.S vaccine against Covid-19. N Engl J Med 2021;384:2187-201.
DOI: https://doi.org/10.1056/NEJMoa2101544
Clemens SAC, Folegatti PM, Emary KRW, et al. Efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine against SARS-CoV-2 lineages circulating in Brazil. Nat Commun 2021;12:5861.
DOI: https://doi.org/10.21203/rs.3.rs-654257/v1
Wu K, Werner AP, Koch M, et al. Serum neutralizing activity elicited by mRNA-1273 vaccine. N Engl J Med 2021;384:1468-70.
DOI: https://doi.org/10.1056/NEJMc2102179
Andrews N, Stowe J, Kirsebom F, et al. Covid-19 vaccine effectiveness against the omicron (B.1.1.529) variant. N Engl J Med 2022;386:1532-46.
DOI: https://doi.org/10.1056/NEJMoa2119451
Collie S, Champion J, Moultrie H, et al. Effectiveness of BNT162b2 vaccine against omicron variant in South Africa. N Engl J Med 2022;386:494-6.
DOI: https://doi.org/10.1056/NEJMc2119270
Khoury DS, Steain M, Triccas JA, et al. Analysis: A meta-analysis of early results to predict vaccine efficacy against omicron. medRxiv 2021.12.13.21267748.
DOI: https://doi.org/10.1101/2021.12.13.21267748
Tseng HF, Ackerson BK, Luo Y, et al. Effectiveness of mRNA-1273 against SARS-CoV-2 omicron and delta variants. medRxiv 2022.01.07.22268919.
DOI: https://doi.org/10.1101/2022.01.07.22268919
Johnson & Johnson. Johnson & Johnson COVID-19 Vaccine demonstrates 85 percent effectiveness against hospitalization in South Africa when omicron was dominant. Accessed on 3 March 2022. Available from: https://www.jnj.com/johnson-johnson-covid-19-vaccine-demonstrates-85-percent-effectiveness-against-hospitalization-in-south-africa-when-omicron-was-dominant
Hall V, Foulkes S, Insalata F, et al. Protection against SARS-CoV-2 after Covid-19 vaccination and previous infection. N Engl J Med 2022;386:1207-20.
DOI: https://doi.org/10.1056/NEJMoa2118691
Katikireddi SV, Cerqueira-Silva T, Vasileiou E, et al. Two-dose ChAdOx1 nCoV-19 vaccine protection against COVID-19 hospital admissions and deaths over time: a retrospective, population-based cohort study in Scotland and Brazil. Lancet 2022;399:25-5.
DOI: https://doi.org/10.1016/S0140-6736(21)02754-9
Feikin DR, Higdon MM, Abu-Raddad LJ, et al. Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: results of a systematic review and meta-regression. Lancet 2022;399:924-44.
DOI: https://doi.org/10.1016/S0140-6736(22)00152-0
How to Cite
Sarkar, Malay, and Irappa Madabhavi. 2022. “SARS-CoV-2 Variants of Concern: A Review”. Monaldi Archives for Chest Disease 93 (3). https://doi.org/10.4081/monaldi.2022.2337.
Copyright (c) 2022 The Author(s)
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