Since the first reported human infection with SARS-CoV-2 in December 2019, many protein subunit vaccines have been proposed for human use. Subunit vaccines Use one or more antigens suitable for eliciting a robust immune response. However, the main concern is the effectiveness of subunit vaccines and elicited antibodies to neutralize variants of SARS-CoV-2 such as B.1.1.7 (alpha), B.1.351 (beta) and P1 (gamma), B.1.617 ( Delta) and C.37 (Lambda). The spike protein (S) is a potential fragment for use as an antigen in vaccine development.
This protein plays a crucial role in the first step of the infection process as it binds to the ACE2 receptor (Angiotensin-Converting Enzyme 2) and after binding it enters the host cell. Immunization-induced specific antibodies against the receptor binding domain (RBD) can block and effectively prevent viral invasion. The focus of this review is the impact of spike mutant variants of SARS-CoV2 (alpha, beta, gamma, delta and lambda) on the efficacy of subunit recombinant vaccines . Little or no significant impact on vaccine efficacy against alpha and delta variants has been reported to date. Such an impact on vaccine efficacy for beta, delta, gamma and lambda variants may be even greater compared to the alpha variant. Still, more comprehensive analyzes are needed to assess the true impact of the SARS-CoV-2 variants on vaccine efficacy.
introduction
The routine status of life in the world has been halted by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. It causes significant health, social and economic burdens worldwide. SARS-CoV-2 is a positive-sense, single-stranded RNA virus that evolves rapidly and continuously accumulates genomic mutations as it continues to be transmitted. Since the first reported human infection with SARS-CoV-2 in Wuhan in December 2019 many protein subunit vaccines have been presented for human use. Nevertheless, viral genome mutations leading to new variants are a real challenge in the global fight against this pandemic. A major focus of this review is to evaluate the impact of spike mutant variants of SARS-CoV2 (B.1.1.7, B.1.351 and B.1.1.28.1) on the efficacy of recombinant subunit vaccines that have been developed to elicit an immune response against the spike protein of SARS-CoV2.
methods
Independent searches of PubMed, Web of Science and Global Index Medicus were conducted by two researchers in June 2021. The search strategy consisted of a word combination covering the following areas (Covid-19 OR SARS-CoV-2) AND vaccine AND B.1.1.7 variant OR B.1.351 variant OR B.1.1.28.1 variant OR B.1.617.2 OR C.37 variant. The search had no geographic or language limitations and included all studies reporting the efficacy of SARS-CoV-2 vaccines against alpha, beta, gamma, delta and lambda variants. Here we narratively describe the most important results of the included studies.
The genomic features of SARS-CoV-2
The SARS-CoV-2 is a spherical virion containing a positive-strand RNA virus with a genome length of approximately 29,700 nucleotides . The 5ˊ end spans more than two-thirds of the genome and includes a long ORF1ab polyprotein that encodes 16 nonstructural proteins. The 3ˊ end encodes four major structural proteins, namely the spike (S) protein, nucleocapsid (N) protein, membrane (M) protein and coat protein (E). In addition, the virus contains six accessory proteins encoded by the genes ORF3a, ORF6, ORF7a, ORF7b, ORF8 and ORF9b. ORF3a is a Transmembrane protein that forms ion channels in the host membrane and encodes ORF7a, a type I transmembrane protein(10). ORF8 is a protein with an N-terminal signal sequence for endoplasmic reticulum transport and ORF9b represses the IFN-I response(9).
Structure, function and antigenicity of the SARS-CoV-2 spike glycoprotein
S protein , a glycoprotein , is a homotrimer that plays a crucial role in the first step of infection. The monomer of S protein contains 1273 amino acids and has a molecular weight of approximately 140 kDa. The primary function of S protein is to bind to the ACE2 (angiotensin-converting enzyme 2) receptor, which after binding enters the host cell. ACE2 is a type I integral membrane protein that functions as a carboxypeptidase and angiotensin Cleaves II to blood pressure regulating angiotensin.
- The virus binds to ACE2 on the host cell (lung, heart, etc.) for viral entry and subsequent pathogenesis, resulting in severe respiratory infection. Therefore, the S protein-ACE2 interaction is an easy target for vaccines. First, it is exposed on the surface and can be directly recognized by the host’s immune system.
- Second, it mediates the interaction with the host cell’s binding to the ACE2 receptor, which is essential for the subsequent entry of the virus into the target cells, causing subsequent pathogenicity . fifteen Finally, the homologous proteins have already been used for vaccine development against SARS-CoV and MERS-CoV and have been shown to be effective.
- The S protein consists of two functional subunits, including an N-terminal S1 subunit (Val16–Gln690). It consists of S1A, S1B, S1C and S1D domains. The latter is responsible for binding to the host cell receptor .
- A C-terminal membrane-proximal S2 subunit contains the essential elements and is responsible for the fusion of the viral and cellular membranes. This subunit consists of four parts, including an internal membrane fusion peptide (FP), two 7-peptide repeats, a membrane-proximal external region, and a transmembrane domain (TM).
- The S1A domain, called the N-terminal domain (NTD), recognizes carbohydrates such as sialic acid , which is required for the virus to attach to the host cell surface. The S1B domain (Arg319–Phe541), termed the receptor binding domain (RBD) of the SARS-CoV-2 spike protein, interacts with the human ACE2 receptor. The S1 subunit can be further defined into two domains referred to as the N-terminal domain (NTD) and the C-terminal domain (CTD). The River Basin District is in the CTD. The structural parts within the S2 subunit include three long α-helices, several α-helical segments, extensive twisted β-sheets, a membrane-spanning α-helix, and an intracellular cysteine-rich segment. Located between the S1 and S2 subunits in SARS-CoV-2, the PRRA sequence motif features a furin cleavage site. In the S2 subunit there is a second proteolytic cleavage site S20, upstream of the fusion peptide. These two interfaces are involved in viral entry into host cells
The S protein is a potential fragment to be used as antigen in vaccine designing including various forms of the full-length S protein, RBD domain, S1 subunit, NTD, and FP. The RBD of S protein interacts with the ACE2 receptor on host cells directly. The RBD immunization-induced specific antibodies may block this recognition and effectively prevent the viral invasion. Most SARS-CoV-2 subunit vaccines currently under development use RBD as the antigen. Moreover, the RBD domain was also used to develop SARS-CoV and MERS-CoV vaccines.
The S protein is a potential fragment to be used as antigen in vaccine designing including various forms of the full-length S protein, RBD domain, S1 subunit, NTD, and FP. The RBD of S protein interacts with the ACE2 receptor on host cells directly. The RBD immunization-induced specific antibodies may block this recognition and effectively prevent the viral invasion. Most SARS-CoV-2 subunit vaccines currently under development use RBD as the antigen. Moreover, the RBD domain was also used to develop SARS-CoV and MERS-CoV vaccines.
Subunit vaccines against SARS-CoV-2
Subunit vaccines use one or more antigens suitable for eliciting a robust immune response. In theory, the subunit vaccine is very easy and safe, but in practice, it requires a suitable adjuvant to stimulate the host immune response. Several previous attempts were partially successful with SARS-CoV. Immunization of animals with the S1 RBD domain fused with the IgG1 FC portion (RBD-FC) induced highly potent antibodies, which could bind with the RBD domain of the S1 domain, completely neutralized SARS-CoV, and inhibited SARS-CoV entry into Vero E6 cells.
SARS-CoV-2 Spike P681H Antibody (Alpha, Mu Variant) |
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9359-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 Spike P681H Antibody (Alpha, Mu Variant) |
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9359-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 Spike P681H Antibody [9F7E4] (Alpha, Mu Variant) |
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PM-9371-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 Spike P681H Antibody [9F7E4] (Alpha, Mu Variant) |
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PM-9371-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 Spike P681H Antibody [1G8D11] (Alpha, Mu Variant) |
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PM-9373-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 Spike P681H Antibody [1G8D11] (Alpha, Mu Variant) |
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PM-9373-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 Spike P681H Antibody [7A4D12](Alpha, Mu Variant) |
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PM-9374-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 Spike P681H Antibody [7A4D12](Alpha, Mu Variant) |
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PM-9374-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 Spike P681H Antibody [7C11H11] (Omicron, Alpha Variant) |
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PM-9375-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 Spike P681H Antibody [7C11H11] (Omicron, Alpha Variant) |
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PM-9375-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 (COVID-19) Alpha Variant (B.1.1.7, UK) Spike P681H Peptide |
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9359P | ProSci | 0.05 mg | 235.5 EUR |
SARS-CoV-2 Spike P26S Antibody (Gamma Variant) |
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9573-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 Spike P26S Antibody (Gamma Variant) |
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9573-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 (COVID-19) Mu Variant (B.1.621) Spike RBD (R346K, E484K, N501Y, D614G, P681H) Recombinant Protein |
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21-830 | ProSci | 0.1 mg | 714.3 EUR |
SARS-CoV-2 (COVID-19) Spike P681R Antibody [5H4C5] (Delta Variant) |
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PM-9677-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 (COVID-19) Spike P681R Antibody [5H4C5] (Delta Variant) |
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PM-9677-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 (COVID-19) Spike P681R Antibody [7E3C5] (Delta Variant) |
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PM-9680-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 (COVID-19) Spike P681R Antibody [7E3C5] (Delta Variant) |
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PM-9680-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 (COVID-19) Spike P26S Antibody [5G12G11] (Gamma Variant) |
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PM-9590-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 (COVID-19) Spike P26S Antibody [5G12G11] (Gamma Variant) |
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PM-9590-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 Spike P26S Peptide (Gamma Variant) |
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9573P | ProSci | 0.05 mg | 235.5 EUR |
SARS-CoV-2 (COVID-19) Spike P681R Peptide (Delta Variant) |
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9673P | ProSci | 0.05 mg | 235.5 EUR |
SARS-CoV-2 (COVID-19) Spike L452R Antibody (Delta Variant) |
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9463-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 (COVID-19) Spike L452R Antibody (Delta Variant) |
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9463-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 (COVID-19) Spike 156-157EFdel Antibody (Delta Variant) |
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9689-002mg | ProSci | 0.02 mg | 229.7 EUR |
SARS-CoV-2 (COVID-19) Spike 156-157EFdel Antibody (Delta Variant) |
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9689-01mg | ProSci | 0.1 mg | 594.26 EUR |
SARS-CoV-2 (COVID-19) Alpha Variant (B.1.1.7, UK) Spike RBD Recombinant Protein |
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21-824 | ProSci | 0.1 mg | 1186.8 EUR |
Spike S1 (B.1.1.7; Alpha Variant) (SARS-CoV-2): ACE2 TR-FRET Assay Kit |
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78282 | BPS Bioscience | 384 rxns. | 930 EUR |
SARS-CoV-2 (COVID-19) Alpha Variant (B.1.1.7, UK) Spike S1 (RBD) Recombinant Protein |
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21-808 | ProSci | 50 ug | 619.8 EUR |
SARS-CoV-2 (COVID-19) Alpha Variant (B.1.1.7, UK) Spike S1 (RBD) Recombinant Protein |
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21-811 | ProSci | 50 ug | 537.9 EUR |
Spike (B.1.621, Mu Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
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78618-1 | BPS Bioscience | 100 µl | 795 EUR |
Spike (B.1.621, Mu Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
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78618-2 | BPS Bioscience | 500 µl x 2 | 3995 EUR |
SARS-CoV-2 (COVID-19) Full-Length Alpha Variant (B.1.1.7, UK) Spike Recombinant Protein |
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21-818 | ProSci | 0.025 mg | 796.2 EUR |
Spike S1 (B.1.618 Variant), Avi-His-Tag (SARS-CoV-2) |
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101126 | BPS Bioscience | 100 µg | 320 EUR |
Spike S1 (B.1.429 Variant), Avi-His-Tag (SARS-CoV-2) |
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101130 | BPS Bioscience | 100 µg | 320 EUR |
Spike S1 (B.1.617.2 Variant) Avi-His-Tag (SARS-CoV-2) |
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101151-1 | BPS Bioscience | 100 µg | 335 EUR |
Spike S1 (B.1.617.2 Variant) Avi-His-Tag (SARS-CoV-2) |
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101151-2 | BPS Bioscience | 1 mg | 2995 EUR |
Spike Trimer (S1+S2) (B.1.351 Variant, Δ242-244) (SARS-CoV-2) |
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101091 | BPS Bioscience | 100 µg | 320 EUR |
Spike RBD (B.1.351 Variant) Avi-His-Tag (SARS-CoV-2) |
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100978-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike RBD (B.1.351 Variant) Avi-His-Tag (SARS-CoV-2) |
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100978-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike S1 (B.1.1.7 Variant), Avi-His-Tag (SARS-CoV-2) |
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101001-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike S1 (B.1.1.7 Variant), Avi-His-Tag (SARS-CoV-2) |
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101001-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike S1 (P.1 Variant), Avi-His-Tag (SARS-CoV-2) |
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101079 | BPS Bioscience | 100 µg | 320 EUR |
Spike RBD (B.1.1.7 Variant), Avi-His-Tag (SARS-CoV-2) |
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100977-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike RBD (B.1.1.7 Variant), Avi-His-Tag (SARS-CoV-2) |
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100977-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike S1 RBD (B.1.1.7; Alpha Variant), Avi-His-Tag, Biotin-Labeled (SARS-CoV-2) HiP™ |
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100999-1 | BPS Bioscience | 25 µg | 295 EUR |
Spike S1 RBD (B.1.1.7; Alpha Variant), Avi-His-Tag, Biotin-Labeled (SARS-CoV-2) HiP™ |
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100999-2 | BPS Bioscience | 50 µg | 435 EUR |
Spike S1 RBD (B.1.1.7; Alpha Variant), Avi-His-Tag, Biotin-Labeled (SARS-CoV-2) HiP™ |
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100999-3 | BPS Bioscience | 500 µg_x000D_ | 3800 EUR |
SARS-CoV-2 (COVID-19) Gamma Variant (P.1, Brazil) Spike S1 (RBD) Variant Recombinant Protein |
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21-810 | ProSci | 50 ug | 619.8 EUR |
SARS-CoV-2 (COVID-19) Gamma Variant (P.1, Brazil) Spike S1 (RBD) Variant Recombinant Protein |
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21-813 | ProSci | 50 ug | 537.9 EUR |
Spike Trimer (S1+S2) (B.1.617 Variant), His-Tag (SARS-CoV-2) |
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101143 | BPS Bioscience | 100 µg | 320 EUR |
Spike Trimer (S1+S2) (B.1.618 Variant), His-Tag (SARS-CoV-2) |
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101145 | BPS Bioscience | 100 µg | 320 EUR |
Spike S1 RBD (B.1.617 Variant), Avi-His-Tag (SARS-CoV-2) |
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101156-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike S1 RBD (B.1.617 Variant), Avi-His-Tag (SARS-CoV-2) |
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101156-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike S1 RBD (B.1.618 Variant), Avi-His-Tag (SARS-CoV-2) |
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101158 | BPS Bioscience | 100 µg | 320 EUR |
Spike Trimer (S1+S2) (B.1.429 Variant) His-Tag (SARS-CoV-2) |
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101057 | BPS Bioscience | 100 µg | 320 EUR |
Spike Trimer (S1+S2) (B.1.351 Variant), His-Tag (SARS-CoV-2) |
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510333-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike Trimer (S1+S2) (B.1.351 Variant), His-Tag (SARS-CoV-2) |
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510333-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike (SARS-CoV-2, UK Variant) Pseudotyped Lentivirus (Luc Reporter) |
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78112-1 | BPS Bioscience | 100 µl | 875 EUR |
Spike (SARS-CoV-2, UK Variant) Pseudotyped Lentivirus (Luc Reporter) |
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78112-2 | BPS Bioscience | 500 µl x 2 | 4405 EUR |
Spike (B.1.351 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
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78142-1 | BPS Bioscience | 100 µl | 860 EUR |
Spike (B.1.351 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
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78142-2 | BPS Bioscience | 500 µl x 2 | 4320 EUR |
Spike (B.1.351 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
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78160-1 | BPS Bioscience | 100 µl | 835 EUR |
Spike (B.1.351 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
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78160-2 | BPS Bioscience | 500 µl x 2 | 4195 EUR |
SARS-CoV-2 (COVID-19) Omicron Variant (B.1.1.529) Spike RBD Recombinant Protein |
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21-844 | ProSci | 0.1 mg | 714.3 EUR |
Spike Trimer (S1+S2) (P.1 Variant), His-Tag (SARS-CoV-2) |
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100989-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike Trimer (S1+S2) (P.1 Variant), His-Tag (SARS-CoV-2) |
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100989-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike Trimer (S1+S2) (B.1.1.7 Variant), His-Tag (SARS-CoV-2) |
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510334-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike Trimer (S1+S2) (B.1.1.7 Variant), His-Tag (SARS-CoV-2) |
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510334-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike S1 (B.1.617 Variant) (SARS-CoV-2): ACE2 TR-FRET Assay Kit |
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78288 | BPS Bioscience | 384 rxns. | 1070 EUR |
Spike S1 (B.1.618 Variant) (SARS-CoV-2): ACE2 TR-FRET Assay Kit |
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78289 | BPS Bioscience | 384 rxns. | 1070 EUR |
SARS-CoV-2 (COVID-19) Omicron Variant (B.1.1.529) Spike Trimer Recombinant Protein |
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21-845 | ProSci | 0.1 mg | 714.3 EUR |
SARS-CoV-2 (COVID-19) Beta Variant ( B.1.351, SA) Spike RBD Recombinant Protein |
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21-825 | ProSci | 0.1 mg | 1186.8 EUR |
SARS-CoV-2 (COVID-19) Variant Spike Protein RBD (E484D) Recombinant Protein |
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21-829 | ProSci | 0.1 mg | 714.3 EUR |
Spike S1 (B.1.617.2.1, Delta Plus Variant) Avi-His-Tag (SARS-CoV-2) |
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101179 | BPS Bioscience | 100 µg | 320 EUR |
Spike (P.1 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
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78144-1 | BPS Bioscience | 100 µl | 835 EUR |
Spike (P.1 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
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78144-2 | BPS Bioscience | 500 µl x 2 | 4195 EUR |
SARS-CoV-2 (COVID-19) Variant (B.1.160, 20A.EU2) Spike RBD (S477N) Recombinant Protein |
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20-181 | ProSci | 0.1 mg | 714.3 EUR |
Spike (B.1.1.7 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
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78158-1 | BPS Bioscience | 100 µl | 835 EUR |
Spike (B.1.1.7 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
|||
78158-2 | BPS Bioscience | 500 µl x 2 | 4195 EUR |
Spike (P.1 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
|||
78159-1 | BPS Bioscience | 100 µl | 835 EUR |
Spike (P.1 Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
|||
78159-2 | BPS Bioscience | 500 µl x 2 | 4195 EUR |
Spike S1 (B.1.617.1 Variant), Avi-His-Tag, Biotin-Labeled (SARS-CoV-2) |
|||
101125-1 | BPS Bioscience | 25 µg | 295 EUR |
Spike S1 (B.1.617.1 Variant), Avi-His-Tag, Biotin-Labeled (SARS-CoV-2) |
|||
101125-2 | BPS Bioscience | 50 µg | 435 EUR |
SARS-CoV-2 (COVID-19) Beta Variant (B.1.351, SA) Spike S1 (RBD) Recombinant Protein |
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21-809 | ProSci | 50 ug | 619.8 EUR |
SARS-CoV-2 (COVID-19) Beta Variant (B.1.351, SA) Spike S1 (RBD) Recombinant Protein |
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21-812 | ProSci | 50 ug | 537.9 EUR |
Spike Trimer (S1+S2) (B.1.617.1, Kappa Variant), His-Tag (SARS-CoV-2) |
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101144-1 | BPS Bioscience | 100 µg | 320 EUR |
Spike Trimer (S1+S2) (B.1.617.1, Kappa Variant), His-Tag (SARS-CoV-2) |
|||
101144-2 | BPS Bioscience | 1 mg | 2850 EUR |
Spike Trimer (S1+S2) (B.1.617.2; Delta Variant), His-Tag (SARS-CoV-2) |
|||
101147 | BPS Bioscience | 100 µg | 320 EUR |
SARS-CoV-2 (COVID-19) UK variant (B.1.1.7) Spike S1 (N501Y) Recombinant Protein |
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11-084 | ProSci | 0.1 mg | 651.3 EUR |
Spike S1 (B.1.351; Beta Variant) (SARS-CoV-2): ACE2 TR-FRET Assay Kit |
|||
78287 | BPS Bioscience | 384 rxns. | 1070 EUR |
Spike (B.1.617.2; Delta Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
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78216-1 | BPS Bioscience | 100 µl | 860 EUR |
Spike (B.1.617.2; Delta Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
|||
78216-2 | BPS Bioscience | 500 µl x 2 | 4320 EUR |
Spike S1 (B.1.617.1; Kappa Variant) (SARS-CoV-2): ACE2 TR-FRET Assay Kit |
|||
78283 | BPS Bioscience | 384 rxns. | 930 EUR |
Spike S1 (B.1.617.2; Delta Variant) (SARS-CoV-2): ACE2 TR-FRET Assay Kit |
|||
78291 | BPS Bioscience | 384 rxns. | 975 EUR |
Spike (BA.2, Omicron Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
|||
78625-1 | BPS Bioscience | 100 µl | 900 EUR |
Spike (BA.2, Omicron Variant) (SARS-CoV-2) Pseudotyped Lentivirus (Luc Reporter) |
|||
78625-2 | BPS Bioscience | 500 µl x 2 | 4510 EUR |
SARS-CoV-2 (COVID-19) Variant (B.1.429, Ca .20C) Spike RBD (L452R) Recombinant Protein |
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20-180 | ProSci | 0.1 mg | 714.3 EUR |
Spike (B.1.1.529, Omicron Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
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78349-1 | BPS Bioscience | 100 µl | 875 EUR |
Spike (B.1.1.529, Omicron Variant) (SARS-CoV-2) Pseudotyped Lentivirus (eGFP Reporter) |
|||
78349-2 | BPS Bioscience | 500 µl x 2 | 4405 EUR |
So far, several companies and academics have started plans on the SARS-CoV-2 subunit vaccine . Almost all of them use the S protein as an antigenic target. For example, Novavax, Inc. announced to have produced multiple nanoparticle vaccine candidates based on S protein. Besides, the Pasteur Institute of Iran and Finley institute of Cuba also prepared subunit vaccines against SARS-CoV-2. To facilitate the development of a SARS-CoV-2 vaccine, the preferred adjuvant varied widely, including the classic aluminum adjuvant that enhances the immune response by facilitating phagocytosis and slowing the diffusion of antigens from the injection site. It can efficiently stimulate the Th2 immune response upon injection. The F59, MF59 have already been used in flu vaccines in Europe and the United States. The mechanism of MF59 is to recruit immune cells to induce antigen-specific immune responses. The adjuvant system (AS) comprises a series of adjuvants improved by GlaxoSmithKline (GSK), including AS01, AS02, AS03 , and AS04 Among them, AS01 is a liposome adjuvant.