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Immunogenicity and Safety Study of Monovalent Omicron XBB.1.5 Vaccine as a Booster in Adults

Phase 3
Withdrawn
Conditions
COVID-19
Interventions
Biological: SCB-2019 vaccine, a monovalent wu-hu1 SARS-CoV-2 trimeric S-protein subunit vaccine for COVID-19
Biological: SCB-2023B vaccine, a monovalent Omicron XBB.1.5 recombinant SARS-CoV-2 trimeric S-protein subunit vaccine for COVID-19
Registration Number
NCT06567457
Lead Sponsor
Clover Biopharmaceuticals AUS Pty Ltd
Brief Summary

The purpose of this study is to assess the immunogenicity and safety of SCB-2023B monovalent Omicron XBB.1.5 vaccine compared to the prototype SCB-2019 vaccine in participants previously vaccinated with 3 doses of inactivated COVID-19 vaccine ≥6 months prior to enrollment.

Detailed Description

The purpose of this study is to assess the immunogenicity and safety of SCB-2023B monovalent Omicron XBB.1.5 vaccine compared to the prototype SCB-2019 vaccine in participants previously vaccinated with 3 doses of inactivated COVID-19 vaccine ≥6 months prior to enrollment.

Recruitment & Eligibility

Status
WITHDRAWN
Sex
All
Target Recruitment
Not specified
Inclusion Criteria
  • Male or female ≥18 years of age.
  • Individuals willing and able to comply with study requirements, including all scheduled visits, vaccinations, laboratory tests and other study procedures.
  • Individuals willing and able to give an informed consent, prior to screening.
  • Healthy participants or participants with pre-existing medical conditions who are in a stable medical condition.
  • Individuals who received three doses of inactivated COVID-19 vaccine
Exclusion Criteria
  • Body temperature >37.8°C (axillary), or any acute illness at baseline.
  • Confirmed SARS-CoV-2 infectionor with known history of COVID-19.
  • Individuals who have received an investigational or licensed COVID-19 vaccine prior to Day 1 (except for inactivated COVID-19 vaccine).
  • Any confirmed or suspected immunosuppressive or immunodeficient condition resulting from disease or immunosuppressive/cytotoxic therapy.
  • Any progressive unstable or uncontrolled clinical conditions.
  • Individuals who are pregnant, or breastfeeding, or planning to become pregnant while enrolled in this study or during the study period.
  • History of severe adverse reaction associated with a vaccine or severe allergic reaction.
  • History of malignancy within 1 year before screening.
  • Individuals who have received any other investigational product.
  • Individuals who have received any other licensed vaccines within 14 days prior to enrollment.
  • Treatment with Rituximab or any other anti-CD20 monoclonal antibodies.
  • Known bleeding disorder that would, in the opinion of the investigator, contraindicate i.m. injection.
  • Administration of intravenous immunoglobulins and/or any blood products.
  • Any condition that, in the opinion of the investigator, would interfere with the primary study objectives or pose additional risk to the participant.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
SCB-2019SCB-2019 vaccine, a monovalent wu-hu1 SARS-CoV-2 trimeric S-protein subunit vaccine for COVID-19Participants will receive one booster dose with SCB-2019 vaccine on Day 1
SCB-2023BSCB-2023B vaccine, a monovalent Omicron XBB.1.5 recombinant SARS-CoV-2 trimeric S-protein subunit vaccine for COVID-19Participants will receive one booster dose with SCB-2023B vaccine on Day 1
Primary Outcome Measures
NameTimeMethod
Assess the reactogenicity of SCB-2023B vaccine compared to SCB-2019 vaccineDay 7

Proportion of participants with local and systemic AEs

GMT ratioDay 15

Demonstrate that SCB-2023B vaccine elicits an immune response superior to SCB-2019 for Omicron XBB.1.5

Assess the safety of SCB-2023B vaccine compared to SCB-2019 vaccineUp to 1 year post-vaccination

Proportion of participants with SAE, AEs leading to early termination from study, MAAEs, and AESIs

Secondary Outcome Measures
NameTimeMethod
SCRsDay 1, 15

Proportion of subjects with seroconversion by virus neutralization assay against new emergent SARS-CoV-2 strains

Proportion of subjects with antibody titer >=LLOQDay 1, 15

Proportion of participants with antibody titer ≥ LLoQ by virus neutralization assay against new emergent SARS-CoV-2 strains

GMFRsDay 1, 15

Geometric mean fold rise elicited by SCB-2023B vaccine and SCB-2019 vaccine by virus neutralization assay against new emergent SARS-CoV-2 strains

Proportion of subjects with antibody titer >=LLOQ by virus neutralization assay against Omicron XBB1.5Day 1, 15, 180

Proportion of participants with antibody titer ≥ LLoQ

Non-inferiority of the Omicron XBB.1.5 immune response elicited by SCB-2023B vaccine versus SARS-CoV-2 Delta titers in a subset of naïve participants of the CLO-SCB-2019-003 clinical study (virus neutralization assay)Day 15

GMT ratio

GMTsDay 1, 15

Geometric mean titers elicited by SCB-2023B vaccine and SCB-2019 vaccine by virus neutralization assay against new emergent SARS-CoV-2 strains

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