journal article·2022-11-04Open access

Silver and Silver Nanoparticles for the Potential Treatment of COVID-19: A Review

Phalalochanan Nair Jayapal Arjun, Bipin Sankar, Karthik V. Shankar, Naveen V. Kulkarni, Subbarayan Sivasankaran, Balakrishnan Shankar

Coatings· Volume 12· Issue 11

Abstract

COVID-19 is an epizootic and life-threatening outbreak affecting millions of people globally. Coronavirus variants have emerged in different locations since their origin. Silver and its compounds, including silver nanoparticles (AgNPs), have been used in the medical field for a long period, especially in surgical treatments. The anti-microbial and anti-viral properties of silver are well documented. These properties depend on the size of the particles, concentration, precursor, method of preparation, and the presence of other benefiting compounds. Several experiments were conducted by researchers worldwide to prove the anti-bacterial and anti-viral properties of silver (Ag) and AgNPs, emphasizing that silver can be introduced to multiple organs in the human body and exhibit the expected antiviral characteristics. In this review article, use of silver nanoparticles to fight the COVID-19 pandemic according with the current information is discussed. The mechanisms involving antiviral activity and toxicity are discussed in detail. This article concludes that strong binding of AgNPs with SARS-CoV-2 virus prevents binding with the host cell, leading to the death of the virus. However, increased cytotoxic effect of the silver compounds at higher concentrations is a matter of concern.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Nanoparticles: synthesis and applications · Healthcare and Environmental Waste Management

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Department of Mechanical Engineering, Mar Baselios College of Engineering and Technology, Trivandrum 695015, India

Department of Mechanical Engineering, Amrita Vishwa Vidyapeetham, Amritapuri 690525, India

Department of Chemistry, Amrita Vishwa Vidyapeetham, Amritapuri 690525, India

Department of Mechanical Engineering, College of Engineering, Qassim University, Buraydah 51452, Saudi Arabia

Funding

Amrita Vishwa Vidyapeetham, Amritapuri, India

References (100+)

Show source-provided references
1. Murarkar, S., Gothankar, J., Doke, P., Dhumale, G., Pore, P.D., Lalwani, S., Quraishi, S., Patil, R.S., Waghachavare, V., and Dhobale, R. (2021). Prevalence of the acute respiratory infections and associated factors in the rural areas and urban slum areas of western Maharashtra, India: A community-based cross-sectional study. Front. Public Health, 9.10.3389/fpubh.2021.723807 ↗
2. Nair, H., Simões, E.A.F., Rudan, I., Gessner, B.D., Azziz-Baumgartner, E., Zhang, J.S.F., Feikin, D.R., Mackenzie, G.A., Moiïsi, J.C., and Roca, A. (2013). Global and regional burden of hospital admissions for severe acute lower respiratory infections in young children in 2010: A systematic analysis. Lancet, 381.10.1016/S0140-6736(12)61901-1 ↗
3. Acter, T., Uddin, N., Das, J., Akhter, A., Choudhury, T.R., and Kim, S. (2020). Evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as coronavirus disease 2019 (COVID-19) pandemic: A global health emergency. Sci. Total Environ., 730.10.1016/j.scitotenv.2020.138996 ↗
4. (2021, September 25). World Health Organization Website. Available online: https://covid19.who.int/.
5. AlSamman, M., Caggiula, A., Ganguli, S., Misak, M., and Pourmand, A. (2020). Non-respiratory presentations of COVID-19, a clinical review. Am. J. Emerg. Med., 38.10.1016/j.ajem.2020.09.054 ↗
6. Joint WHO-China Study Team (2021). WHO-convened global study of origins of SARS-CoV-2: China part (text extract). Infect. Dis. Immun., 1.10.1097/ID9.0000000000000017 ↗
7. Jayaweera, M., Perera, H., Gunawardana, B., and Manatunge, J. (2020). Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy. Environ. Res., 188.10.1016/j.envres.2020.109819 ↗
8. Burke, R.M., Midgley, C.M., Dratch, A., Fenstersheib, M., Haupt, T., Holshue, M., Ghinai, I., Jarashow, M.C., Lo, J., and McPherson, T.D. (2020). Active monitoring of persons exposed to patients with confirmed COVID-19—United States, January–February 2020. Morb. Mortal. Wkly. Rep., 69.10.15585/mmwr.mm6909e1 ↗
9. Guo, Y., Korteweg, C., McNutt, M.A., and Gu, J. (2008). Pathogenetic mechanisms of severe acute respiratory syndrome. Virus Res., 133.10.1016/j.virusres.2007.01.022 ↗
10. Wang, W., Xu, Y., Gao, R., Lu, R., Han, K., Wu, G., and Tan, W. (2020). Detection of SARS-CoV-2 in different types of clinical specimens. JAMA, 23.10.1001/jama.2020.3786 ↗
11. Chang, L., Zhao, L., Gong, H., Wang, L., and Wang, L. (2020). Severe acute respiratory syndrome coronavirus 2 RNA detected in blood donations. Emerg. Infect. Dis., 26.10.3201/eid2607.200839 ↗
12. Chang, L., Yan, Y., and Wang, L. (2020). Coronavirus disease 2019: Coronaviruses and blood safety. Transfus. Med. Rev., 34.10.1016/j.tmrv.2020.02.003 ↗
13. Xu, J., Zhao, S., Teng, T., Abdalla, A.E., Zhu, W., Xie, L., Wang, Y., and Guo, X. (2020). Systematic Comparison of Two Animal-to-Human Transmitted Human Coronaviruses: SARS-CoV-2 and SARS-CoV. Viruses, 12.10.3390/v12020244 ↗
14. Thippareddi, H., Balamurugan, S., Patel, J., Singh, M., and Brassard, J. (2020). Coronaviruses–Potential human threat from foodborne transmission?. Lebensm Wiss Technol., 134.10.1016/j.lwt.2020.110147 ↗
15. Kwok, Y.L.A., Gralton, J., and McLaws, M.L. (2015). Face touching: Un hábito frecuente que tiene implicaciones para la higiene de las manos. Am. J. Infectar., 43.10.1016/j.ajic.2014.10.015 ↗
16. Kampf, G., Todt, D., Pfaender, S., and Steinmann, E. (2020). A review and analysis Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. J. Hosp. Infect., 104.10.1016/j.jhin.2020.01.022 ↗
17. Casanova, L.M., Jeon, S., Rutala, W.A., Weber, D.J., and Sobsey, M.D. (2010). Effects of air temperature and relative humidity on coronavirus survival on surfaces. Appl. Environ. Microbiol., 76.10.1128/AEM.02291-09 ↗
18. Sizun, J., Yu, M.W.N., and Talbot, P.J. (2000). Survival of human coronaviruses 229E and OC43 in suspension and after drying onsurfaces: A possible source ofhospital-acquired infections. J. Hosp. Infect., 46.10.1053/jhin.2000.0795 ↗
19. Duan, S.-M., Zhao, X.-S., Wen, R.-F., Huang, J.J., Pi, G.-H., Zhang, S.-X., Sheng, J.H., Bi, L., Ruan, L., and Dong, X.-P. (2003). Stability of SARS coronavirus in human specimens and environment and its sensitivity to heating and UV irradiation. Biomed. Environ. Sci., 16.
20. Sportelli, C.N. (2020). Materials Science Help the Fight against SARS-CoV-2. Nanomaterials, 10.10.3390/nano10040802 ↗
21. Govind, V., Bharadwaj, S., Sai Ganesh, M.R., Vishnu, J., Shankar, K.V., Shankar, B., and Rajesh, R. (2021). Antiviral properties of copper and its alloys to inactivate covid-19 virus: A review. Biometals, 34.10.1007/s10534-021-00339-4 ↗
22. Wang, L., Hu, C., and Shao, L. (2017). The antimicrobial activity of nanoparticles: Present situation and prospects for the future. Int. J. Nanomed., 12.10.2147/IJN.S121956 ↗
23. Filler matrix interfaces of inorganic/biopolymer composites and their applications10.1016/B978-0-08-102665-6.00004-2 ↗
24. Longano, D., Ditaranto, N., Sabbatini, L., Torsi, L., and Cioffi, N. (2012). Synthesis and antimicrobial activity of copper nanomaterials. Nano-Antimicrobials, Springer.10.1007/978-3-642-24428-5_3 ↗
25. Bogdanovic, U., Vodnik, V., Mitric, M., Dimitrijevic, S., Skapin, S.D., Zunic, V., Budimir, M., and Stoiljkovic, M. (2015). Nanomaterial with High Antimicrobial Efficacy Copper/Polyaniline Nanocomposite. ACS Appl. Mater. Interfaces, 7.10.1021/am507746m ↗
26. Galúcio, J.M.P., de Souza, S.G.B., Vasconcelos, A.A., Lima, A.K.O., da Costa, K.S., de Campos Braga, H., and Taube, P.S. (2022). Synthesis, characterization, applications, and toxicity of green synthesized nanoparticles. Curr. Pharm. Biotechnol., 23.10.2174/1389201022666210521102307 ↗
27. Chiriac, V., Stratulat, D.N., Calin, G., Nichitus, S., Burlui, V., Stadoleanu, C., Popa, M., and Popa, I.M. (2016). Antimicrobial property of zinc based nanoparticles. IOP Conference Series: Materials Science and Engineering, IOP Publishing.10.1088/1757-899X/133/1/012055 ↗
28. Mishra, P.K., Mishra, H., Ekielski, A., Talegaonkar, S., and Vaidya, B. (2017). Zinc oxide nanoparticles: A promising nanomaterial for biomedical applications. Drug Discov. Today, 22.10.1016/j.drudis.2017.08.006 ↗
29. Król, A., Pomastowski, P., Ranska, K., Railean-Plugaru, V., and Buszewski, B. (2017). Zinc oxide nanoparticles: Synthesis, antiseptic activity and toxicity mechanism. Adv. Colloid Interface Sci., 249.10.1016/j.cis.2017.07.033 ↗
30. Vimbela, G.V., Ngo, S.M., Fraze, C., Yang, L., and Stout, D.A. (2017). Antibacterial properties and toxicity from metallic nanomaterials. Int. J. Nanomed., 12.10.2147/IJN.S134526 ↗
31. Balraj, B., Senthilkumar, N., Potheher, I.V., and Arulmozhi, M. (2018). Characterization, antibacterial, anti-arthritic and in-vitro cytotoxic potentials of biosynthesized magnesium oxide nanomaterial. Mater. Sci. Eng. B, 231.10.1016/j.mseb.2018.10.011 ↗
32. Lansdown, A.B.G. (2006). Silver in health care: Antimicrobial effects and safety in use. Biofunctional Text. Ski., 33.10.1159/000093928 ↗
33. Melayie, A., and Youngs, J.W. (2005). Silver and its application on antimicrobial agents. Expert. Opin. Ther. Pat., 15.10.1517/13543776.15.2.125 ↗
34. Walker, M., and Parsons, D. (2014). The biological fate of silver ions following the use of silver-containing wound care products–a review. Int. Wound J., 11.10.1111/j.1742-481X.2012.01115.x ↗
35. Ratan, Z.A., Mashrur, F.R., Chhoan, A.P., Shahriar, S.M., Haidere, M.F., Runa, N.J., Kim, S., Kweon, D.-H., Hosseinzadeh, H., and Cho, J.Y. (2021). Silver nanoparticles as potential antiviral agents. Pharmaceutics, 13.10.3390/pharmaceutics13122034 ↗
36. Galdiero, S., Falanga, A., Vitiello, M., Cantisani, M., Marra, V., and Galdiero, M. (2011). Silver nanoparticles as potential antiviral agents. Molecules, 16.10.3390/molecules16108894 ↗
37. Holden, N.E. (2019). History of the Origin of the Chemical Elements and Their Discoverers, Brookhaven National Lab. (BNL).
38. Barillo, D.J., and Marx, D.E. (2014). Silver in medicine: A brief history BC 335 to present. Burns, 40.10.1016/j.burns.2014.09.009 ↗
39. Leone, G., Pepi, S., Consumi, M., Mahdizadeh, F.F., Lamponi, S., and Magnani, A. (2021). Phosphorylated xanthan gum-Ag (I) complex as antibacterial viscosity enhancer for eye drops formulation. Carbohydr. Polym., 267.10.1016/j.carbpol.2021.118196 ↗
40. Kremer, J.R., Mastronarde, D.N., and McIntosh, J.R. (1996). Computer visualization of three-dimensional image data using IMOD. J. Struct. Biol., 116.10.1006/jsbi.1996.0013 ↗
41. Ludwigson, D.C., and Mears, D.C. (1964). Today’s prosthetic metals. J. Miner. Met. Mater. Soc., 16.10.1007/BF03378265 ↗
42. Konop, M., Damps, T., Misicka, A., and Rudnicka, L. (2016). Certain aspects of silver and silver nanoparticles in wound care: A minireview. J. Nanomater., 2016.10.1155/2016/7614753 ↗
43. Pietro Reverberi, A., Vocciante, M., Salerno, M., Ferretti, M., and Fabiano, B. (2020). Green synthesis of silver nanoparticles by low-energy wet bead milling of metal spheres. Materials, 13.10.3390/ma13010063 ↗
44. Zakaria, M.A., Menazea, A.A., Mostafa, A.M., and Al-Ashkar, E.A. (2020). Ultra-thin silver nanoparticles film prepared via pulsed laser deposition: Synthesis, characterization, and its catalytic activity on reduction of 4-nitrophenol. Surf. Interfaces, 19.10.1016/j.surfin.2020.100438 ↗
45. Semenova, A.A., Ivanov, V.K., Savilov, S.V., and Goodilin, E.A. (2013). Unusual silver nanostructures prepared by aerosol spray pyrolysis. CrystEngComm, 15.10.1039/c3ce41077c ↗
46. Colson, P., Henrist, C., and Cloots, R. (2013). Nanosphere lithography: A powerful method for the controlled manufacturing of nanomaterials. J. Nanomater., 2013.10.1155/2013/948510 ↗
47. Rivero, P.J., Urrutia, A., Goicoechea, J., Zamarreño, C.R., Arregui, F.J., and Matías, I.R. (2011). An antibacterial coating based on a polymer/sol-gel hybrid matrix loaded with silver nanoparticles. Nanoscale Res. Lett., 6.10.1186/1556-276X-6-305 ↗
48. Nasretdinova, G.R., Fazleeva, R.R., Mukhitova, R.K., Nizameev, I.R., Kadirov, M.K., Ziganshina, A.Y., and Yanilkin, V.V. (2015). Electrochemical mediated synthesis of silver nanoparticles in solution. Russ. J. Electrochem., 51.10.1134/S1023193515110129 ↗
49. Raza, S. (2016). Shape-Dependent Antibacterial Studies of Silver Nanoparticles Synthesized by Wet Chemical Routes. Nanomaterials, 6.10.3390/nano6040074 ↗
50. Borase, H.P., Salunke, B.K., Salunkhe, R.B., Patil, C.D., Hallsworth, J.E., Kim, B.S., and Patil, S.V. (2014). Plant extract: A promising biomatrix for ecofriendly, controlled synthesis of silver nanoparticles. Appl. Biochem. Biotechnol., 173.10.1007/s12010-014-0831-4 ↗
51. Maya, F., Muhl, S., Peña, O., and Miki-Yoshida, M. (2009). Synthesis and characterization of silver–carbon nanoparticles produced by high-current pulsed arc. Thin Solid Films, 518.10.1016/j.tsf.2009.09.090 ↗
52. Ratte, H.T. (1999). Bioaccumulation and toxicity of silver compounds: A review. Environ. Toxicol. Chem. Int. J., 18.10.1897/1551-5028(1999)018<0089:BATOSC>2.3.CO;2 ↗
53. Hollinger, M.A. (1996). Toxicological aspects of topical silver pharmaceuticals. Crit. Rev. Toxicol., 26.10.3109/10408449609012524 ↗
54. Parveen, K., Banse, V., and Ledwani, L. (2016). Green synthesis of nanoparticles: Their advantages and disadvantages. AIP Conference Proceedings, AIP Publishing LLC.10.1063/1.4945168 ↗
55. Hayat, M., Uzair, M., Ali Syed, R., Arshad, M., and Bashir, S. (2022). Status of COVID-19 vaccination around South Asia. Hum. Vaccin. Immunother., 18.10.1080/21645515.2021.2016010 ↗
56. Marshall, J.P., and Schneider, R.P. (1977). Systemic argyria secondary to topical silver nitrate. Arch. Dermatol., 113.10.1001/archderm.1977.01640080079013 ↗
57. Fung, M.C., and Bowen, D.L. (1996). Silver products for medical indications: Risk-benefit assessment. J. Toxicol. Clin. Toxicol., 34.10.3109/15563659609020246 ↗
58. Tashi, T., Gupta, N.V., and Mbuya, V.B. (2016). Silver nanoparticles: Synthesis, mechanism of antimicrobial action, characterization, medical applications, and toxicity effects. J. Chem. Pharm. Res., 8.
59. Griffitt, R.J., Luo, J., Gao, J., Bonzongo, J., and Barber, D.S. (2008). Effects of particle composition and species on toxicity of metallic nanomaterials in aquatic organisms. Environ. Toxicol. Chem. Int. J., 27.10.1897/08-002.1 ↗
60. Rezvani, E., Rafferty, A., McGuinness, C., and Kennedy, J. (2019). Adverse effects of nanosilver on human health and the environment. Acta Biomater., 94.10.1016/j.actbio.2019.05.042 ↗
61. Ayrault, S., Priadi, C.R., Evrard, O., Lefèvre, I., and Bonté, P. (2010). Silver and thallium historical trends in the Seine River basin. J. Environ. Monit., 12.10.1039/c0em00153h ↗
62. Rai, M., and Agarkar, G. (2016). Plant–fungal interactions: What triggers the fungi to switch among lifestyles?. Crit. Rev. Microbiol., 42.10.3109/1040841X.2014.958052 ↗
63. Furno, F., Morley, K.S., Wong, B., Sharp, B.L., Arnold, P.L., Howdle, S.M., Bayston, R., Brown, P.D., Winship, P.D., and Reid, H.J. (2004). Silver nanoparticles and polymeric medical devices: A new approach to prevention of infection?. J. Antimicrob. Chemother., 54.10.1093/jac/dkh478 ↗
64. Maillard, J.-Y., and Hartemann, P. (2013). Silver as an antimicrobial: Facts and gaps in knowledge. Crit. Rev. Microbiol., 39.10.3109/1040841X.2012.713323 ↗
65. Silver as antibacterial agent: Ion, nanoparticle, and metal10.1002/anie.201205923 ↗
66. Silver in medicine: The basic science10.1016/j.burns.2014.09.010 ↗
67. Damm, C., Münstedt, H., and Rösch, A. (2008). The antimicrobial efficacy of polyamide 6/silver-nano-and microcomposites. Mater. Chem. Phys., 108.10.1016/j.matchemphys.2007.09.002 ↗
68. Anastasiadis, S.H., Chrissopoulou, K., and Frick, B. (2008). Structure and dynamics in polymer/layered silicate nanocomposites. Mater. Sci. Eng. B, 152.10.1016/j.mseb.2008.06.008 ↗
69. Chen, M., Wang, M.-Y., Han, J.-T., Zhang, J.-Y., Li, Z.-Y., and Qian, D.-J. (2006). Preparation and study of polyacryamide-stabilized silver nanoparticles through a one-pot process. J. Phys. Chem. B, 110.10.1021/jp061134n ↗
70. Rong, C., Chen, Y., Chen, C., Hu, L., Wang, H., and Li, Y. (2022). Toward simultaneous compatibilization and nucleation of fully biodegradabe nanocomposites: Effect of nanorod-assisted interfacial stereocomplex crystals in immiscible polymer blends. Compos. Part B Eng., 234.10.1016/j.compositesb.2022.109708 ↗
71. Bragg, P.D., and Rainnie, D.J. (1974). The effect of silver ions on the respiratory chain of Escherichia coli. Can. J. Microbiol., 20.10.1139/m74-135 ↗
72. Kędziora, A., Speruda, M., Krzyżewska, E., Rybka, J., Łukowiak, A., and Bugla-Płoskońska, G. (2018). Similarities and differences between silver ions and silver in nanoforms as antibacterial agents. Int. J. Mol. Sci., 19.10.3390/ijms19020444 ↗
73. Möhler, J.S., Sim, W., Blaskovich, M.A.T., Cooper, M.A., and Ziora, Z.M. (2018). Silver bullets: A new lustre on an old antimicrobial agent. Biotechnol. Adv., 36.10.1016/j.biotechadv.2018.05.004 ↗
74. Lansdown, A.B.G., and Williams, A. (2004). How safe is silver in wound care?. J. Wound Care, 13.10.12968/jowc.2004.13.4.26596 ↗
75. Silver absorption and antibacterial efficacy of silver dressings10.12968/jowc.2005.14.4.26762 ↗
76. Nqakala, Z.B., Sibuyi, N.R.S., Fadaka, A.O., Meyer, M., Onani, M.O., and Madiehe, A.M. (2021). Advances in nanotechnology towards development of silver nanoparticle-based wound-healing agents. Int. J. Mol. Sci., 22.10.3390/ijms222011272 ↗
77. Lee, S.H., and Jun, B.-H. (2019). Silver nanoparticles: Synthesis and application for nanomedicine. Int. J. Mol. Sci., 20.10.3390/ijms20040865 ↗
78. Lansdown, A.B.G. (2004). A review of the use of silver in wound care: Facts and fallacies. Br. J. Nurs., 13.10.12968/bjon.2004.13.Sup1.12535 ↗
79. Multiple parameters for the comprehensive evaluation of the susceptibility of Escherichia coli to the silver ion10.1023/A:1009253223055 ↗
80. Spacciapoli, P., Buxton, D., Rothstein, D., and Friden, P. (2001). Antimicrobial activity of silver nitrate against periodontal pathogens. J. Periodontal Res., 36.10.1034/j.1600-0765.2001.360207.x ↗
81. Teirumnieks, E., Balchev, I., Ghalot, R.S., and Lazov, L. (2020). Antibacterial and anti-viral effects of silver nanoparticles in medicine against COVID-19—A review. Laser Phys., 31.10.1088/1555-6611/abc873 ↗
82. Nazeruddin, G.M., Prasad, N.R., Prasad, S.R., Shaikh, Y.I., Waghmare, S.R., and Adhyapak, P. (2014). Coriandrum sativum seed extract assisted in situ green synthesis of silver nanoparticle and its anti-microbial activity. Ind. Crops Prod., 60.10.1016/j.indcrop.2014.05.040 ↗
83. Mpenyana-Monyatsi, L., Mthombeni, N.H., Onyango, M.S., and Momba, M.N.B. (2012). Cost-effective filter materials coated with silver nanoparticles for the removal of pathogenic bacteria in groundwater. Int. J. Environ. Res. Public Health, 9.10.3390/ijerph9010244 ↗
84. Ahmadi, S. (2020). The importance of silver nanoparticles in human life. Adv. Appl. NanoBio-Technol., 1.10.47277/AANBT/1(1)9 ↗
85. Xiang, D., Zheng, Y., Duan, W., Li, X., Yin, J., Shigdar, S., O’Connor, M.L., Marappan, M., Zhao, X., and Miao, Y. (2013). Inhibition of A/Human/Hubei/3/2005 (H3N2) influenza virus infection by silver nanoparticles in vitro and in vivo. Int. J. Nanomed., 8.10.2147/IJN.S57432 ↗
86. Siadati, S.A., Afzali, M., and Sayyadi, M. (2020). Could silver nano-particles control the 2019-nCoV virus?; An urgent glance to the past. Chem. Rev. Lett., 3.
87. Behbudi, G. (2021). Effect of silver nanoparticles disinfectant on covid-19. Adv. Appl. NanoBio-Technol., 2.
88. Synthesis and effect of silver nanoparticles on the antibacterial activity of different antibiotics against Staphylococcus aureus and Escherichia coli, Nanomedicine Nanotechnology
89. Fisman, D.N., and Tuite, A.R. (2021). Evaluation of the relative virulence of novel SARS-CoV-2 variants: A retrospective cohort study in Ontario, Canada. Cmaj, 193.10.1503/cmaj.211248 ↗
90. Sokhansanj, B.A., Zhao, Z., and Rosen, G.L. (2021). Interpretable and predictive deep modeling of the SARS-CoV-2 spike protein sequence. medRxiv.10.1101/2021.12.26.21268414 ↗
91. Caputo, V., Calvino, G., Strafella, C., Termine, A., Fabrizio, C., Trastulli, G., Ingrascì, A., Peconi, C., Bardini, S., and Rossini, A. (2022). Tracking the Initial Diffusion of SARS-CoV-2 Omicron Variant in Italy by RT-PCR and Comparison with Alpha and Delta Variants Spreading. Diagnostics, 12.10.3390/diagnostics12020467 ↗
92. Boshier, F.A.T., Venturini, C., Stirrup, O., Guerra-Assunção, J.A., Alcolea-Medina, A., Becket, A.H., Byott, M., Charalampous, T., da Silva Filipe, A., and Frampton, D. (2021). The Alpha variant was not associated with excess nosocomial SARS-CoV-2 infection in a multi-centre UK hospital study. J. Infect., 83.10.1016/j.jinf.2021.09.022 ↗
93. Brejová, B., Hodorová, V., Boršová, K., Čabanová, V., Szemes, T., Mišík, M., Klempa, B., Nosek, J., and Vinař, T. (2021). Sequencing SARS-CoV-2 in Slovakia: An Unofficial Genomic Surveillance Report. medRxiv.10.1101/2021.07.13.21260431 ↗
94. Salleh, M.Z., Derrick, J.P., and Deris, Z.Z. (2021). Structural evaluation of the spike glycoprotein variants on SARS-CoV-2 transmission and immune evasion. Int. J. Mol. Sci., 22.10.3390/ijms22147425 ↗
95. Islam, S., Islam, T., and Islam, M.R. (2022). New coronavirus variants are creating more challenges to global healthcare system: A brief report on the current knowledge. Clin. Pathol., 15.10.1177/2632010X221075584 ↗
96. Nangunoori, S., Appavu, R., and Kethar, J. (2021). The Connection between COVID-19 Variants (Gamma and Delta Variant) and Demographics Using Python. J. Stud. Res., 10.10.47611/jsrhs.v10i4.2138 ↗
97. CDC COVID-19 Vaccine Breakthrough Case Investigations Team, Birhane, M., Bressler, S., Chang, G., Clark, T., Dorough, L., Fischer, M., Watkins, L.F., Goldstein, J.M., and Kugeler, K. (2021). COVID-19 vaccine breakthrough infections reported to CDC—United States, January 1–April 30, 2021. Morb. Mortal. Wkly. Rep., 70.10.15585/mmwr.mm7021e3 ↗
98. Johnsen, U., Sutter, J., Schulz, A., Tästensen, J., and Schönheit, P. (2015). XacR—A novel transcriptional regulator of D-xylose and L-arabinose catabolism in the haloarchaeon H aloferax volcanii. Environ. Microbiol., 17.10.1111/1462-2920.12603 ↗
99. Maggi, F., Novazzi, F., Genoni, A., Baj, A., Spezia, P.G., Focosi, D., Zago, C., Colombo, A., Cassani, G., and Pasciuta, R. (2021). Imported SARS-CoV-2 variant P. 1 in traveler returning from Brazil to Italy. Emerg. Infect. Dis., 27.10.3201/eid2704.210183 ↗
100. Carroll, T., Fox, D., van Doremalen, N., Ball, E., Morris, M.K., Sotomayor-Gonzalez, A., Servellita, V., Rustagi, A., Yinda, C.K., and Fritts, L. (2022). The B. 1.427/1.429 (epsilon) SARS-CoV-2 variants are more virulent than ancestral B. 1 (614G) in Syrian hamsters. PLoS Pathog., 18.10.1101/2021.08.25.457626 ↗