1. Colmenares V. Protein structural comparison between COVID-19 and other coronaviruses. 2020; 1: 1-6
2. Rossi GA, Sacco O, Mancino E, Cristiani L, Midulla F. Differences and similarities between SARS-CoV and SARS-CoV-2: spike receptor-binding domain recognition and host cell infection with support of cellular serine proteases. Infection 2020; 48: 665-669.
3. Hu B, Guo H, Zhou P, Shi Z-L. Characteristics of SARS-CoV-2 and COVID-19. Nat Rev Microbial 2021; 19:141-154.
4. Ou X, Liu Y, Lei X, Li P, Mi D, Ren L, et al. Characterization of spike glycoprotein of SARS-CoV-2 on virus entry and its immune cross-reactivity with SARS-CoV. Nat Commun 2020; 11:1-12.
5. Andersen KG, Rambaut A, Lipkin WI, Holmes EC, Garry RF. The proximal origin of SARS-CoV-2. Nat Med 2020;
6. Liu H, Wei P, Zhang Q, Aviszus K, Linderberger J, Yang J, et al. The lambda variant of SARS-CoV-2 has a better chance than the delta variant to escape vaccines. BioRxiv 2021; 1-26.
7. Sanches PR, Charlie-Silva I, Braz HL, Bittar C, Calmon MF, Rahal P, et al. Recent advances in SARS-CoV-2 spike protein and RBD mutations comparison between new variants alpha (B. 1.1.7, United Kingdom), beta (B. 1.351, South Africa), gamma (P. 1, Brazil) and delta (B. 1.617. 2, India). J Virus Erad 2021; 7:100054-100061.
8. Zinatizadeh MR, Zarandi PK, Zinatizadeh M, Yousefi MH, Amani J, Rezaei N. Efficacy of mRNA, adenoviral vector, and perfusion protein COVID-19 vaccines. Biomed Pharmacother 2022; 146:112527-112536.
9. Liu Z, Xu W, Xia S, Gu C, Wang X, Wang Q, et al. RBD-Fc-based COVID-19 vaccine candidate induces highly potent SARS-CoV-2 neutralizing antibody response. Signal Transduct Target Ther 2020; 5:1-10.
10. Dong Y, Dai T, Wei Y, Zhang L, Zheng M, Zhou F. A systematic review of SARS-CoV-2 vaccine candidates. Signal Transduct Target Ther 2020; 5:1-14.
11. Loes AN, Gentles LE, Greaney AJ, Crawford KH, Bloom JD. Attenuated influenza virions expressing the SARS-CoV-2
receptor-binding domain induces neutralizing antibodies in mice. Viruses 2020; 12:987-999.
12. Min L, Sun Q. Antibodies and vaccines target RBD of SARS-CoV-2. Front Mol Biosci 2021; 8:247-256.
13. Vartak A, Suchecki SJ. Recent advances in subunit vaccine carriers. Vaccines 2016; 4:12-30.
14. Yu F, Xiang R, Deng X, Wang L, Yu Z, Tian S, et al. Receptor binding domain-specific human neutralizing monoclonal
antibodies against SARS-CoV and SARS-CoV-2. Signal Transduct Target Ther 2020; 5:1-12.
15. Chen J, Miao L, Li J-M, Li Y-Y, Zhu Q-Y, Zhou C-L, et al. Receptor-binding domain of SARS-Cov spike protein: soluble expression in E. coli, purification, and functional characterization. World J Gastroenterol 2005; 11:6159-6164.
16. Du L, Zhao G, Chan CC, Sun S, Chen M, Liu Z, et al. Recombinant receptor-binding domain of SARS-CoV spike
protein expressed in mammalian, insect, and Escherichia coli cells elicits potent neutralizing antibody and protective immunity. Virology
17. Pollet J, Chen W-H, Strych U. Recombinant protein vaccines, a proven approach against coronavirus pandemics. Adv Drug Deliv Rev 2021; 170:71-82.
18. Merkuleva IA, Shcherbakov DN, Borgoyakova MB, Shanshin DV, Rudometov AP, Karpenko LI, et al. Comparative
immunogenicity of the recombinant receptor-binding domain of protein S SARS-CoV-2 obtained in prokaryotic and mammalian expression systems. Vaccines 2022; 10:96-106.
19. Sinegubova MV, Orlova NA, Kovnir SV, Dayanova LK, Vorobiev II. High-level expression of the monomeric SARS-CoV-2 S protein RBD 320-537 in stably transfected CHO cells by the EEF1A1-based plasmid vector. PloS One 2021; 16:1-19.
20. De March M, Terdoslavich M, Polesz S, Guarnaccia C, Poggianella M, Marcello A, et al. Expression, purification and
characterization of SARS-CoV-2 spike RBD in ExpiCHO cells. Protein Expr Purif 2022; 194:106071-106077.
21. Yang J, Wang W, Chen Z, Lu S, Yang F, Bi Z, et al. A vaccine targeting the RBD of the S protein of SARS-CoV-2 induces
protective immunity. Nature 2020; 586:572-577.
22. Zang J, Zhu Y, Zhou Y, Gu C, Yi Y, Wang S, et al. Yeast produced RBD-based recombinant protein vaccines elicit broadly
neutralizing antibodies and durable protective immunity against SARS-CoV-2 infection. Cell Discov 2021; 7:1-16.
23. Dalvie NC, Rodriguez-Aponte SA, Hartwell BL, Tostanoski LH, Biedermann AM, Crowell LE, et al. Engineered SARS-CoV-2 receptor binding domain improves manufacturability in yeast and immunogenicity in mice. Proc Natl Acad Sci U S A 2021; 118:1-9.
24. Maharjan PM, Cheon J, Jung J, Kim H, Lee J, Song M, et al. Plant-expressed receptor binding domain of the SARS-CoV-2
spike protein elicits humoral immunity in mice. Vaccines 2021; 9:978-793.
25. Siriwattananon K, Manopwisedjaroen S, Shanmugaraj B, Rattanapisit K, Phumiamorn S, Sapsutthipas S, et al. Plant produced receptor-binding domain of SARS-CoV-2 elicits potent neutralizing responses in mice and non-human primates. Front Plant Sci 2021; 12:847-862.
26. Prahlad J, Struble LR, Lutz WE, Wallin SA, Khurana S, Schnaubelt A, et al. Bacterial expression and purification of
functional recombinant SARS-CoV-2 spike receptor binding domain. Protein Sci 2021; 30:1983-1990.
27. He Y, Qi J, Xiao L, Shen L, Yu W, Hu T. Purification and characterization of the receptor‐binding domain of SARS‐CoV‐2
spike protein from Escherichia coli. Eng Life Sci 2021; 21:453-460.
28. Liu L, Chen T, Zhou L, Sun J, Li Y, Nie M, et al. A bacterially expressed SARS-CoV-2 receptor binding domain fused with cross-reacting material 197 A-domain elicits high level of neutralizing antibodies in mice. Front Microbiol 2022; 13:854630-854643.
29. Ke Q, Sun P, Wang T, Mi T, Xu H, Wu J, et al. Non-glycosylated SARS-CoV-2 RBD elicited a robust neutralizing antibody response in mice. Immunotechnology 2022; 113279:1-8.
30. Brindha S, Kuroda Y. A multi-disulfide receptor-binding domain (RBD) of the SARS-CoV-2 spike protein expressed in Escherichia coli using a SEP-Tag produces antisera interacting with the mammalian cell expressed spike (S1) protein. Int J Cell Sci Mol Biol 2022; 23:1703-1715.