The Emergence of SARS-CoV-2 Variants: Comparison
Please note this is a comparison between Version 2 by Conner Chen and Version 1 by Ananda Tiwari.

The emergence of new variants of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) associated with varying infectivity, pathogenicity, diagnosis, and effectiveness against treatments challenged the overall management of the coronavirus disease 2019 (COVID-19) pandemic. 

  • COVID-19
  • SARS-CoV-2 variants
  • Alpha (B.1.1.7)

1. Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), continuously underwent mutations leading to the emergence of new variants [1]. These variants are of great concern [2[2][3][4],3,4], as they might be associated with increased infectivity [1[1][5],5], severity [1[1][6][7],6,7], could have higher shedding rates [8], the potential to escape natural or vaccine-induced immunity [9,10][9][10], and can also affect the performance of diagnostic methodologies [11,12][11][12]. Such changes in virus characteristics affected the overall management plan for the COVID-19 pandemic. For example, it led to travel restrictions both locally and internationally for people from infected areas [1,7][1][7], and many more consequences on the daily lives of individuals. Therefore, the emergence of SARS-CoV-2 variants increased the need for genomic surveillance and other innovative tools to protect public health.
Whole-genome sequencing (WGS) of clinical specimens is a primary approach for identifying new emerging variants [13], by comparing the sample genome with the reference genome [14]. However, using WGS for monitoring each clinical specimen is time-consuming, labor-intensive, and expensive, and is usually conducted for individuals with clinical symptoms. Many of the COVID-19-infected individuals can be asymptomatic, so only relying on a clinical monitoring approach in the surveillance can miss the mutant variants carried by asymptomatic individuals.
Wastewater surveillance (WWS), also known as wastewater-based epidemiology (WBE), of infectious diseases through analyzing municipal sewage proved to be a cost-effective approach for monitoring the circulation of SARS-CoV-2 at a population level, covering both symptomatic and asymptomatic individuals [15,16,17,18,19,20][15][16][17][18][19][20]. In contrast to the clinical approach, WWS is a comprehensive, rapid technique for regular monitoring and tracking of the possible emergence of new variants at a population level [19,20,21,22,23][19][20][21][22][23]. From a surveillance point of view, municipal raw sewage can be a good material for SARS-CoV-2 monitoring, as it comprises the entire population of a community, both healthy and infected individuals (symptomatic, asymptomatic, pre-symptomatic, and post-symptomatic), contributing through feces, nasal mucus, and sputum to sewage from households, hospitals, and nursing homes [16,17,24][16][17][24]. Globally, many studies reported monitoring different variants of SARS-CoV-2 in wastewater [11[11][15][16][17][20][24][25][26][27][28],15,16,17,20,24,25,26,27,28], thereby highlighting WWS as an alternative tool for detecting different variants in communities. However, a comprehensive evaluation of the state-of-art use of WWS for monitoring SARS-CoV-2 variants is lacking. Such data can help evaluate and optimize WWS for monitoring SARS-CoV-2 variants. Such information can also be useful in managing future infectious outbreaks, such as how the wild and mutated variants differ among geological locations.

2. The Emergence of SARS-CoV-2 Variants

SARS-CoV-2 is an enveloped single-strand RNA (ssRNA) virus belonging to the Coronaviridae family and genus Betacoronavirus [9,29][9][29]. As with other ssRNA viruses, SARS-CoV-2 contains RNA-dependent RNA polymerase (RdRP), which is responsible for sub-genomic mRNA synthesis for producing viral proteins, including the virus envelope and spike proteins [30]. RNA viruses are relatively prone to adapt more rapidly to a changed environment by changing their genome structure. SARS-CoV-2 continuously evolves into new variants due to genetic mutation and viral recombination [1,2,13,31][1][2][13][31]. Mutation refers to at least a single change in a virus’s genetic code. Genetic modifications can change the virus’s characteristics [1]. A SARS-CoV-2 variant can have one or more mutations that differentiate its features from other variants. SARS-CoV-2 has a similar mutation mechanism to other ssRNA viruses that lack proofreading capability, giving rise to new variants [25]. Uncorrected mutations occur during genome replication, recombination, and RNA editing by the deaminase of the infected host [13]. A recombinant variant is created due to a combination of genetic material from two different variants, and a mutant variant is created due to a mutation in RNA. A lineage is a group of closely related viruses with a common ancestor [32]. The ancestral SARS-CoV-2 (wild variant) genome evolved into several lineages (https://cov-lineages.org/lineage_list.html, accessed on 28 November 2022), such as the Alpha (B.1.1.7), Delta (B. 1.617.2), and Omicron (B.1.1.529) [2,3[2][3][7][11][28][32][33][34][35][36][37],7,11,28,32,33,34,35,36,37], due to exposure to some selective pressure [38]. Most of these new variants were developed due to viral spike protein (S-protein) mutation [39].

2.1. Alpha (B.1.1.7 and Q Lineages)

The Alpha variant was first isolated in the United Kingdom in September 2020 and was followed by an upsurge in infection in December 2020 [40]. Soon after, it became the dominant variant until August 2021 in many countries, including the US, India, Sweden, and globally in at least 189 countries (Table 1). The World Health Organization (WHO) classified the Alpha variant as a variant of concern (VOC) on 29 December 2020 [10], after rising hospitalization cases and creating a strain on the public health system and facilities across countries [41]. The Alpha variant was reported to be about 100-fold more lethal than the original SARS-CoV-2 strain [6]. Further, mRNA vaccines were reported to be about 68% less effective against this variant [6]. On 21 September 2021, the WHO designated the Alpha variant as the “variant being monitored” [1,7][1][7]. After 2022, this variant’s circulation drastically reduced worldwide, following the emergence of Delta variants, probably due to the impact on vaccine-induced immunity (Table 1).
Table 1. SARS-CoV-2 variants and lineages [1,7,33].
SARS-CoV-2 variants and lineages [1][7][33].

References

  1. CDC. SARS-CoV-2 Variant Classifications and Definitions. Available online: https://www.cdc.gov/coronavirus/2019-ncov/variants/variant-classifications.html (accessed on 27 May 2022).
  2. Cosar, B.; Karagulleoglu, Z.Y.; Unal, S.; Ince, A.T.; Uncuoglu, D.B.; Tuncer, G.; Kilinc, B.R.; Ozkan, Y.E.; Ozkoc, H.C.; Demir, I.N.; et al. SARS-CoV-2 Mutations and Their Viral Variants. Cytokine Growth Factor Rev. 2022, 63, 10–22.
  3. Callaway, E. Remember Beta? New Data Reveal Variant’s Deadly Powers. Nature 2021.
  4. Wilton, T.; Bujaki, E.; Klapsa, D.; Majumdar, M.; Zambon, M.; Fritzsche, M.; Mate, R.; Martin, J. Rapid Increase of SARS-CoV-2 Variant B.1.1.7 Detected in Sewage Samples from England between October 2020 and January 2021. mSystems 2021, 6, e0035321.
  5. Yurkovetskiy, L.; Wang, X.; Pascal, K.E.; Tomkins-Tinch, C.; Nyalile, T.P.; Wang, Y.; Baum, A.; Diehl, W.E.; Dauphin, A.; Carbone, C.; et al. Structural and Functional Analysis of the D614G SARS-CoV-2 Spike Protein Variant. Cell 2020, 183, 739–751.e8.
  6. Radvak, P.; Kwon, H.J.; Kosikova, M.; Ortega-Rodriguez, U.; Xiang, R.; Phue, J.N.; Shen, R.F.; Rozzelle, J.; Kapoor, N.; Rabara, T.; et al. SARS-CoV-2 B.1.1.7 (Alpha) and B.1.351 (Beta) Variants Induce Pathogenic Patterns in K18-HACE2 Transgenic Mice Distinct from Early Strains. Nat. Commun. 2021, 12, 6559.
  7. WHO. Tracking SARS-CoV-2 Variants. Available online: https://www.who.int/activities/tracking-SARS-CoV-2-variants (accessed on 15 December 2022).
  8. Saguti, F.; Magnil, E.; Enache, L.; Patzi, M.; Johansson, A. Surveillance of Wastewater Revealed Peaks of SARS-CoV-2 Preceding Those of Hospitalized Patients with COVID-19. Water Res. 2020, 189, 116620.
  9. La Rosa, G.; Mancini, P.; Bonanno Ferraro, G.; Veneri, C.; Iaconelli, M.; Lucentini, L.; Bonadonna, L.; Brusaferro, S.; Brandtner, D.; Fasanella, A.; et al. Rapid Screening for SARS-CoV-2 Variants of Concern in Clinical and Environmental Samples Using Nested RT-PCR Assays Targeting Key Mutations of the Spike Protein. Water Res. 2020, 197, 117104.
  10. Wang, P.; Nair, M.S.; Liu, L.; Iketani, S.; Luo, Y.; Guo, Y.; Wang, M.; Yu, J.; Zhang, B.; Kwong, P.D.; et al. Antibody Resistance of SARS-CoV-2 Variants B.1.351 and B.1.1.7. Nature 2021, 593, 130–135.
  11. Vo, V.; Tillett, R.L.; Papp, K.; Shen, S.; Gu, R.; Gorzalski, A.; Siao, D.; Markland, R.; Chang, C.-L.; Baker, H.; et al. Use of Wastewater Surveillance for Early Detection of Alpha and Epsilon SARS-CoV-2 Variants of Concern and Estimation of Overall COVID-19 Infection Burden. Sci. Total Environ. 2022, 835, 155410.
  12. Bei, Y.; Pinet, K.; Vrtis, K.B.; Borgaro, J.G.; Sun, L.; Campbell, M.; Apone, L.; Langhorst, B.W.; Nichols, N.M. Overcoming Variant Mutation-Related Impacts on Viral Sequencing and Detection Methodologies. Front. Med. 2022, 9, 989913.
  13. Ugurel, O.M.; Ata, O.; Turgut-Balik, D. An Updated Analysis of Variations in SARS-CoV-2 Genome. Turk. J. Biol. 2020, 44, 157–167.
  14. Yin, R.; Kwoh, C.K.; Zheng, J. Whole Genome Sequencing Analysis. In Encyclopedia of Bioinformatics and Computational Biology; Elsevier: Amsterdam, The Netherlands, 2019; pp. 176–183.
  15. Tiwari, A.; Lipponen, A.; Hokajärvi, A.-M.; Luomala, O.; Sarekoski, A.; Rytkönen, A.; Österlund, P.; Al-Hello, H.; Juutinen, A.; Miettinen, I.T.; et al. Detection and Quantification of SARS-CoV-2 RNA in Wastewater Influent in Relation to Reported COVID-19 Incidence in Finland. Water Res. 2022, 215, 118220.
  16. Ahmed, W.; Angel, N.; Edson, J.; Bibby, K.; Bivins, A.; O’Brien, J.W.; Choi, P.M.; Kitajima, M.; Simpson, S.L.; Li, J.; et al. First Confirmed Detection of SARS-CoV-2 in Untreated Wastewater in Australia: A Proof of Concept for the Wastewater Surveillance of COVID-19 in the Community. Sci. Total Environ. 2020, 728, 138764.
  17. Sherchan, S.P.; Shahin, S.; Ward, L.M.; Tandukar, S.; Aw, T.G.; Schmitz, B.; Ahmed, W.; Kitajima, M. First Detection of SARS-CoV-2 RNA in Wastewater in North America: A Study in Louisiana, USA. Sci. Total Environ. 2020, 743, 140621.
  18. Pérez-Cataluña, A.; Chiner-Oms, Á.; Cuevas-Ferrando, E.; Díaz-Reolid, A.; Falcó, I.; Randazzo, W.; Girón-Guzmán, I.; Allende, A.; Bracho, M.A.; Comas, I.; et al. Spatial and Temporal Distribution of SARS-CoV-2 Diversity Circulating in Wastewater. Water Res. 2022, 211, 118007.
  19. Fontenele, R.S.; Kraberger, S.; Hadfield, J.; Driver, E.M.; Bowes, D.; Holland, L.A.; Faleye, T.O.C.; Adhikari, S.; Kumar, R.; Inchausti, R.; et al. High-Throughput Sequencing of SARS-CoV-2 in Wastewater Provides Insights into Circulating Variants. Water Res. 2021, 205, 117710.
  20. Islam, M.A.; Rahman, M.A.; Jakariya, M.; Bahadur, N.M.; Hossen, F.; Mukharjee, S.K.; Hossain, M.S.; Tasneem, A.; Haque, M.A.; Sera, F.; et al. A 30-Day Follow-up Study on the Prevalence of SARS-CoV-2 Genetic Markers in Wastewater from the Residence of COVID-19 Patient and Comparison with Clinical Positivity. Sci. Total Environ. 2023, 858, 159350.
  21. Tiwari, A.; Adhikari, S.; Kaya, D.; Islam, M.A.; Malla, B.; Sherchan, S.P.; Al-Mustapha, A.I.; Kumar, M.; Aggarwal, S.; Bhattacharya, P.; et al. Monkeypox Outbreak: Wastewater and Environmental Surveillance Perspective. Sci. Total Environ. 2022, 856, 159166.
  22. Tiwari, A.; Paakkanen, J.; Österblad, M.; Kirveskari, J.; Hendriksen, R.S.; Heikinheimo, A. Wastewater Surveillance Detected Carbapenemase Enzymes in Clinically Relevant Gram-Negative Bacteria in Helsinki, Finland; 2011–2012. Front. Microbiol. 2022, 13, 887888.
  23. Martin, J.; Klapsa, D.; Wilton, T.; Zambon, M.; Bentley, E.; Bujaki, E.; Fritzsche, M.; Mate, R.; Majumdar, M. Tracking SARS-CoV-2 in Sewage: Evidence of Changes in Virus Variant Predominance during COVID-19 Pandemic. Viruses 2020, 12, 1144.
  24. Hokajärvi, A.M.; Rytkönen, A.; Tiwari, A.; Kauppinen, A.; Oikarinen, S.; Lehto, K.M.; Kankaanpää, A.; Gunnar, T.; Al-Hello, H.; Blomqvist, S.; et al. The Detection and Stability of the SARS-CoV-2 RNA Biomarkers in Wastewater Influent in Helsinki, Finland. Sci. Total Environ. 2021, 770, 145274.
  25. Wurtzer, S.; Waldman, P.; Levert, M.; Cluzel, N.; Almayrac, J.L.; Charpentier, C.; Masnada, S.; Gillon-Ritz, M.; Mouchel, J.M.; Maday, Y.; et al. SARS-CoV-2 Genome Quantification in Wastewaters at Regional and City Scale Allows Precise Monitoring of the Whole Outbreaks Dynamics and Variants Spreading in the Population. Sci. Total Environ. 2022, 810, 152213.
  26. Ahmed, W.; Bertsch, P.M.; Angel, N.; Bibby, K.; Bivins, A.; Dierens, L.; Edson, J.; Ehret, J.; Gyawali, P.; Hamilton, K.A.; et al. Detection of SARS-CoV-2 RNA in Commercial Passenger Aircraft and Cruise Ship Wastewater: A Surveillance Tool for Assessing the Presence of COVID-19 Infected Travellers. J. Travel Med. 2020, 27, taaa116.
  27. Gonzalez, R.; Curtis, K.; Bivins, A.; Bibby, K.; Weir, M.H.; Yetka, K.; Thompson, H.; Keeling, D.; Mitchell, J.; Gonzalez, D. COVID-19 Surveillance in Southeastern Virginia Using Wastewater-Based Epidemiology. Water Res. 2020, 186, 116296.
  28. La Rosa, G.; Brandtner, D.; Mancini, P.; Veneri, C.; Ferraro, G.B.; Bonadonna, L.; Lucentini, L.; Suffredini, E. Key Sars-Cov-2 Mutations of Alpha, Gamma, and Eta Variants Detected in Urban Wastewaters in Italy by Long-Read Amplicon Sequencing Based on Nanopore Technology. Water 2021, 13, 2503.
  29. Tiwari, A.; Phan, N.; Tandukar, S.; Ashoori, R.; Thakali, O.; Mousazadesh, M.; Dehghani, M.H.; Sherchan, S.P. Persistence and Occurrence of SARS-CoV-2 in Water and Wastewater Environments: A Review of the Current Literature. Environ. Sci. Pollut. Res. 2021, 29, 85658–85668.
  30. Kitajima, M.; Ahmed, W.; Bibby, K.; Carducci, A.; Gerba, C.P.; Hamilton, K.A.; Haramoto, E.; Rose, J.B. SARS-CoV-2 in Wastewater: State of the Knowledge and Research Needs. Sci. Total Environ. 2020, 739, 139076.
  31. Naqvi, A.A.T.; Fatima, K.; Mohammad, T.; Fatima, U.; Singh, I.K.; Singh, A.; Atif, S.M.; Hariprasad, G.; Hasan, G.M.; Hassan, M.I. Insights into SARS-CoV-2 Genome, Structure, Evolution, Pathogenesis and Therapies: Structural Genomics Approach. Biochim. Biophys. Acta (BBA)-Mol. Basis Dis. 2020, 1866, 165878.
  32. Rambaut, A.; Holmes, E.C.; O’Toole, Á.; Hill, V.; McCrone, J.T.; Ruis, C.; du Plessis, L.; Pybus, O.G. A Dynamic Nomenclature Proposal for SARS-CoV-2 Lineages to Assist Genomic Epidemiology. Nat. Microbiol. 2020, 5, 1403–1407.
  33. ECDC. SARS-CoV-2 Variants of Concern as of 8 December 2022. Available online: https://www.ecdc.europa.eu/en/covid-19/variants-concern (accessed on 15 December 2022).
  34. da Silva, J.C.; Félix, V.B.; Leão, S.A.B.F.; Trindade-Filho, E.M.; Scorza, F.A. New Brazilian Variant of the SARS-CoV-2 (P1/Gamma) of COVID-19 in Alagoas State. Braz. J. Infect. Dis. 2021, 25, 101588.
  35. Wadman, M. California Coronavirus Strain May Be More Infectious—And Lethal. Science 2021, 23, abh2101.
  36. Kimura, I.; Kosugi, Y.; Wu, J.; Zahradnik, J.; Yamasoba, D.; Butlertanaka, E.P.; Tanaka, Y.L.; Uriu, K.; Liu, Y.; Morizako, N.; et al. The SARS-CoV-2 Lambda Variant Exhibits Enhanced Infectivity and Immune Resistance. Cell Rep. 2022, 38, 110218.
  37. Acevedo, M.L.; Gaete-Argel, A.; Alonso-Palomares, L.; de Oca, M.M.; Bustamante, A.; Gaggero, A.; Paredes, F.; Cortes, C.P.; Pantano, S.; Martínez-Valdebenito, C.; et al. Differential Neutralizing Antibody Responses Elicited by CoronaVac and BNT162b2 against SARS-CoV-2 Lambda in Chile. Nat. Microbiol. 2022, 7, 524–529.
  38. López-Cortés, G.I.; Palacios-Pérez, M.; Zamudio, G.S.; Veledíaz, H.F.; Ortega, E.; José, M.V. Neutral Evolution Test of the Spike Protein of SARS-CoV-2 and Its Implications in the Binding to ACE2. Sci. Rep. 2021, 11, 18847.
  39. Itarte, M.; Bofill-Mas, S.; Martínez-Puchol, S.; Torrell, H.; Ceretó, A.; Carrasco, M.; Forés, E.; Canela, N.; Girones, R.; Rusiñol, M. Looking for a Needle in a Haystack. SARS-CoV-2 Variant Characterization in Sewage. Curr. Opin. Environ. Sci. Health 2021, 24, 100308.
  40. Walker, A.S.; Vihta, K.-D.; Gethings, O.; Pritchard, E.; Jones, J.; House, T.; Bell, I.; Bell, J.I.; Newton, J.N.; Farrar, J.; et al. Tracking the Emergence of SARS-CoV-2 Alpha Variant in the United Kingdom. N. Engl. J. Med. 2021, 385, 2582–2585.
  41. Davies, N.G.; Abbott, S.; Barnard, R.C.; Jarvis, C.I.; Kucharski, A.J.; Munday, J.D.; Pearson, C.A.B.; Russell, T.W.; Tully, D.C.; Washburne, A.D.; et al. Estimated Transmissibility and Impact of SARS-CoV-2 Lineage B.1.1.7 in England. Science 2021, 372, eabg3055.
  42. Liu, C.; Ginn, H.M.; Dejnirattisai, W.; Supasa, P.; Wang, B.; Tuekprakhon, A.; Nutalai, R.; Zhou, D.; Mentzer, A.J.; Zhao, Y.; et al. Reduced Neutralization of SARS-CoV-2 B.1.617 by Vaccine and Convalescent Serum. Cell 2021, 184, 4220–4236.e13.
  43. Yaniv, K.; Ozer, E.; Lewis, Y.; Kushmaro, A. RT-QPCR Assays for SARS-CoV-2 Variants of Concern in Wastewater Reveals Compromised Vaccination-Induced Immunity. Water Res. 2021, 207, 117808.
  44. Yaniv, K.; Ozer, E.; Shagan, M.; Lakkakula, S.; Plotkin, N.; Bhandarkar, N.S.; Kushmaro, A. Direct RT-QPCR Assay for SARS-CoV-2 Variants of Concern (Alpha, B.1.1.7 and Beta, B.1.351) Detection and Quantification in Wastewater. Environ. Res. 2021, 201, 111653.
  45. Hodcroft, E.B.; Zuber, M.; Nadeau, S.; Vaughan, T.G.; Crawford, K.H.D.; Althaus, C.L.; Reichmuth, M.L.; Bowen, J.E.; Walls, A.C.; Corti, D.; et al. Spread of a SARS-CoV-2 Variant through Europe in the Summer of 2020. Nature 2021, 595, 707–712.
  46. Maida, C.M.; Amodio, E.; Mazzucco, W.; La Rosa, G.; Lucentini, L.; Suffredini, E.; Palermo, M.; Andolina, G.; Iaia, F.R.; Merlo, F.; et al. Wastewater-Based Epidemiology for Early Warning of SARS-CoV-2 Circulation: A Pilot Study Conducted in Sicily, Italy. Int. J. Hyg. Environ. Health 2022, 242, 113948.
  47. Sharif, S.; Ikram, A.; Khurshid, A.; Salman, M.; Mehmood, N.; Arshad, Y.; Ahmed, J.; Safdar, R.M.; Rehman, L.; Mujtaba, G.; et al. Detection of SARs-CoV-2 in Wastewater Using the Existing Environmental Surveillance Network: A Potential Supplementary System for Monitoring COVID-19 Transmission. PLoS ONE 2021, 16, e0249568.
  48. Sidik, S.M. Vaccines Protect against Infection from Omicron Subvariant—But Not for Long. Nature 2022.
  49. Jensen, B.; Luebke, N.; Feldt, T.; Keitel, V.; Brandenburger, T.; Kindgen-Milles, D.; Lutterbeck, M.; Freise, N.F.; Schoeler, D.; Haas, R.; et al. Emergence of the E484K Mutation in SARS-CoV-2-Infected Immunocompromised Patients Treated with Bamlanivimab in Germany. Lancet Reg. Health-Eur. 2021, 8, 100164.
  50. Kreier, F. Long-COVID Symptoms Less Likely in Vaccinated People, Israeli Data Say. Nature 2022.
  51. Abdool Karim, S.S.; de Oliveira, T. New SARS-CoV-2 Variants—Clinical, Public Health, and Vaccine Implications. N. Engl. J. Med. 2021, 384, 1866–1868.
More
Video Production Service