Our scientific publications on pre-clinical and clinical research and development activities are available for healthcare professionals.
Title: Boosting with adjuvanted SCB-2019 elicits superior Fcγ-receptor engagement driven by IgG3 to SARS-CoV-2 spike
January, 2024
Summary: Protein-based vaccines, such as SCB-2019, can be produced on a large scale at a low cost while antigen design and adjuvant use can modulate efficacy and safety. While effective humoral immunity against SARS-CoV-2 variants has been shown to depend on both neutralization and Fc-mediated immunity, data on the effectiveness of protein-based vaccines with enhanced Fc-mediated immunity is limited. Here, we assess the humoral profile, including antibody isotypes, subclasses, and Fc receptor binding generated by a boosting with a recombinant trimer-tag protein vaccine SCB-2019. Overall, this highlights the potential of SCB-2019 as a cost-efficient boosting regimen effective across variants of concerns.
Title: Six-month safety follow-up of an adjuvanted SARS-CoV-2 trimeric S-protein subunit vaccine (SCB-2019) in adults: a phase 2/3, double-blind, randomized study
February, 2023
Summary: As part of our Phase 2/3 Trial, SPECTRA, SCB-2019 (CpG 1018/Alum) demonstrated a favorable safety profile for adults 18 years and older who received two doses of the vaccine, with a small number of adverse events reported in similar frequencies across both treatment and control groups over the six-month follow-up period.
Title: Immunogenicity of an adjuvanted SARS-CoV-2 trimeric S-protein subunit vaccine (SCB-2019) in SARS-CoV-2-naïve and exposed individuals in a Phase 2/3, double-blind, randomized study
February, 2023
Summary: As part of our Phase 2/3 Trial, SPECTRA, one dose of SCB-2019 (CpG 1018/Alum) was immunogenic in SARS-CoV-2-exposed individuals, while two doses were required to induce an immune response in SARS-CoV-2-naïve individuals. SCB-2019 (CpG 1018/Alum) also elicited a cross-neutralizing response against emergent SARS-CoV-2 variants at antibody levels associated with clinical protection.
Title: Heterologous boosting of neutralizing activity against Delta and Omicron SARS-CoV-2 variants in CoronaVac-primed adults; a randomized study with SCB-2019 vaccine
December, 2022
Summary: The study randomly assigned adults immunized with two doses of inactivated vaccine to receive homologous (inactivated) or heterologous (recombinant protein vaccine, SCB-2019 (CpG 1018/Alum)) booster doses. Among adults who previously received inactivated vaccine, heterologous boosting with SCB-2019 (CpG 1018/Alum) was well tolerated with superior immunogenicity than homologous boosting, particularly for newly emerged variants.
Title: Impact of vaccination with SCB-2019 COVID-19 vaccine on transmission of SARS-CoV-2 infection: a household contact study in the Philippines
November, 2022
Summary: This exploratory, prospective household transmission study, nested within our Phase 2/3 Trial, SPECTRA, demonstrated that vaccination with our COVID-19 vaccine candidate, SCB-2019 (CpG 1018/Alum), reduced SARS-CoV-2 transmission in households, thus decreasing infections among household contacts, compared with placebo.
Title: Homologous and heterologous boosting of the ChAdOx1-S1-S COVID-19 vaccine with the SCB-2019 vaccine candidate: a randomized, observer-blinded, controlled, phase 2 study
August, 2022
Summary: This Phase 2 study demonstrated that SCB-2019 (CpG 1018/Alum), a COVID-19 vaccine candidate, induced higher levels of neutralizing antibodies when administered as a heterologous booster compared to the homologous booster group. All individuals in the study had received two doses of AstraZeneca's vaccine for primary vaccination.
Title: Protection from Omicron and other VOCs by Bivalent S-Trimer™ COVID-19 Vaccine
June, 2022
Summary: This study presents findings from a pre-clinical study of a bivalent SARS-CoV-2 vaccine candidate including both Ancestor and Omicron variant S-proteins, generated using the Trimer-Tag™ platform. It demonstrated that this SARS-CoV-2 bivalent S-Trimer subunit vaccine elicited high titers of neutralizing antibodies against all VOCs, with markedly enhanced Omicron specific neutralizing antibody responses.
Title: Impact of previous exposure to SARS-CoV-2 and of S-Trimer (SCB-2019) COVID-19 vaccination on the risk of reinfection: a randomised, double-blinded, placebo-controlled, phase 2 and 3 trial
April, 2022
Summary: This study presents secondary analyses to calculate the protective efficacy due to previous exposure to SARS-CoV-2 against reinfection with COVID-19 according to severity in SPECTRA participants who had evidence of exposure to SARS-CoV-2 at baseline. Previous exposure to SARS-CoV-2 decreased the risk and severity of subsequent COVID-19 infection, even against newly emerging variants. Protection is further enhanced by one or two doses of SCB-2019.
Title: Efficacy of the adjuvanted subunit protein COVID-19 vaccine, SCB-2019: a phase 2 and 3 multicentre, double-blind, randomised, placebo-controlled trial
January, 2022
Summary: Two doses of SCB-2019 vaccine plus CpG and alum provides notable protection against the entire severity spectrum of COVID-19 caused by circulating SAR-CoV-2 viruses, including the predominating delta variant.
Title: Immunogenicity of SCB-2019 coronavirus disease 2019 vaccine compared with 4 approved vaccines
November, 2021
Summary: In this study, we assessed the immune response against the original SARS-CoV-2 elicited by the adjuvanted S-Trimer vaccine, SCB-2019 (CpG 1018/Alum), in the same assay and laboratory as 4 COVID-19 vaccines approved in 2019. Responses to SCB-2019 were comparable or superior for antibody to original and Alpha variant. The comparison accurately predicted success of the recently reported efficacy trial of SCB-2019 vaccine. Immunogenicity comparisons to original strain and variants of concern should be considered as a basis for authorization of vaccines.
Title: Persistence of the Immune Responses and Cross-Neutralizing Activity With Variants of Concern Following 2 Doses of Adjuvanted SCB-2019 Coronavirus Disease 2019 Vaccine
September, 2021
Summary: SCB-2019 dose-dependently induced immune responses against wild-type SARS-CoV-2, which persisted up to day 184. Neutralizing antibodies were cross-reactive against 3 of the most prevalent variants of concern VoCs.
Title: Broad Neutralization Against SARS-CoV-2 Variants Induced By A Modified B.1.351 Protein-based COVID-19 Vaccine Candidate
May, 2021
Summary: In a mouse immunogenicity study, two doses of a modified B.1.351 spike (S)-Trimer vaccine (B.1.351 S-Trimer) candidate can induce strong humoral immune responses that can broadly neutralize both the original SARS-CoV-2 strain (Wuhan-Hu-1) and Variants of Concern (VOCs), including the UK variant (B.1.1.7), South African variant (B.1.351) and Brazil variant (P.1).
Title: Cryo-EM Structure Of S-Trimer, A Subunit Vaccine Candidate For COVID-19
May, 2021
Summary: In this study, using Trimer-Tag technology, the investigators were able to produce stable and large quantities of WT S-Trimer, a subunit vaccine candidate for COVID-19 with high safety and efficacy from animal and phase 1 clinical trial studies. Cryo-EM structures of the S-Trimer subunit vaccine candidate show that it predominately adopts a tightly closed prefusion state and resembles the native and full-length spike in detergent, confirming its structural integrity.
Title: Safety And Immunogenicity Of S-Trimer (SCB-2019), A Protein Subunit Vaccine Candidate For COVID-19 In Healthy Adults: A Phase 1, Randomised, Double-Blind, Placebo-Controlled Trial
February, 2021
Summary: The SCB-2019 vaccine, comprising S-Trimer protein formulated with either AS03 or CpG/Alum adjuvants, elicited robust humoral and cellular immune responses against SARS-CoV-2, with high viral neutralising activity. Both adjuvanted vaccine formulations were well tolerated and are suitable for further clinical development.
Title: S-Trimer, A COVID-19 Subunit Vaccine Candidate, Induces Protective Immunity In Nonhuman Primates
February, 2021
Summary: Rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.
Title: Improvement Of Pharmacokinetic Profile Of TRAIL Via Trimer-Tag Enhances Its Antitumor Activity In Vivo
August, 2017
Summary: TNF-related apoptosis-inducing ligand (TRAIL/Apo2L) has long been considered a tantalizing target for cancer therapy because it mediates activation of the extrinsic apoptosis pathway in a tumor-specific manner by binding to and trimerizing its functional receptors DR4 or DR5. This study provides direct evidence for the in vivo antitumor efficacy of TRAIL being proportional to systemic drug exposure and suggests that the previous clinical failures may have been due to rapid systemic clearance of native TRAIL and poor apoptosis-inducing potency of dimeric agonist mAbs despite their long serum half-lives.
Title: Functional Detection Of TNF Receptor Family Members By Affinity-Labeled Ligands
July, 2017
Summary: This study shows that TNF receptor family members are heat-stable and can be recognized both in vitro and in vivo by their ligands labeled with alkaline phosphatase. Such an approach may be used in lieu of antibodies for the identification of the cell types involved in receptor signaling during disease onset and progression.
Title: A Broad Blockade Of Signaling From The IL-20 Family Of Cytokines Potently Attenuates Collagen-Induced Arthritis
October, 2016
Summary: In situ ligand–receptor functional binding analysis shows that a large amount of immune infiltrates expressing high levels of TNFR and IL-20 subfamily cytokines congregate within the inflamed disease tissues. Colocalization experiments reveal that signals from IL-20R2 and TNF transduction pathways seem to converge in macrophages and function in tandem in orchestrating the pathogenesis of RA. Elucidation of this interaction provides a better understanding of cytokine cross-talk in RA and a rationale for more effective biologic therapies that target IL-20R2 instead of individual cytokines from IL-20 family.
Title: High Level Expression And Purification Of Recombinant Proteins From Escherichia Coli With AK-TAG
May, 2016
Summary: Adenylate kinase (AK) from Escherichia coli was used as both solubility and affinity tag for recombinant protein production. When fused to the N-terminus of a target protein, an AK fusion protein could be expressed in soluble form and purified to near homogeneity in a single step from Blue-Sepherose via affinity elution with micromolar concentration of P1, P5- di (adenosine—5') pentaphosphate (Ap5A), a transition-state substrate analog of AK. AK-TAG is a new addition to the arsenal of existing affinity tags for recombinant protein expression and purification, and is particularly useful where soluble expression and high degree of purification are at stake.
Title: Alternative Splicing Directs Two IL-20R2 Isoforms And Is Responsible For The Incomplete Gene Knockout Via The Exon I Ablation
March, 2016
Summary: Two heterodimeric receptors consisting of interleukin (IL)-20R2 are shared by three of the IL-20 family of cytokines, IL-19, IL-20 and IL-24. Along with IL-22, these cytokines are downstream effectors of IL-23 and have been implicated in keratinocyte functions and the pathogenesis of psoriasis. This study concludes that the apparent disparity may result from a new IL-20R2 isoform encoded by an alternatively spliced transcript which survived the previous attempt for IL-20R2 gene knockout via the exon I deletion.
Title: PKILLIN: A Versatile Positive-Selection Cloning Vector Based On The Toxicity Of Killin In Escherichia Coli
July, 2014
Summary: Insertion inactivation of killin within the multiple cloning site via either blunt- or sticky-end ligation not only serves as a highly efficient cloning trap, but also may allow any cloned genes to be expressed as His-tagged fusion proteins for subsequent purification. Therefor, pKILLIN is a versatile positive-selection vector ideal for cloning PCR products, making DNA libraries, as well as routine cloning and bacterial expression of genes.