NCT05087368

Brief Summary

SARS-CoV-2 is a highly transmissible and pathogenic coronavirus that emerged in late 2019 and has caused a pandemic of acute respiratory disease, collectively called coronavirus disease-19 (COVID-19). SARS-CoV-2 has a high transmission rate, and severe cases of COVID-19 require admission to hospital intensive care units with the need for mechanical ventilation and associated high mortality. Currently cases continue to rise in many countries as the 'second and third waves' of SARS-CoV-2 infection evolve. The authorized vaccines and most vaccines in development are focused on the major antigenic target of the virus, the SARS-CoV-2 spike (S) protein. Authorization was granted in Brazil by ANVISA for the Fiocruz/Oxford-AstraZeneca ChAdOx1-S COVID-19 vaccine as a 2-dose homologous vaccination regimen, 28- to 84-days apart. Emergency Use Authorization (EUA) was also granted for Sinovac Biotech's CoronaVac vaccine as a 2-dose homologous vaccination regimen, 28 days apart. Further vaccines, using different platforms are approved or expected to be approved for use against SARS-CoV-2. Most of the vaccines are expected to be authorized as 2-dose, homologous vaccination series. SCB-2019 is Clover's adjuvanted recombinant SARS-CoV-2 trimeric S-protein subunit vaccine. The SCB-2019 antigen includes SARS-CoV-2 S protein as a trimer fused to Trimer-Tag and is produced in Chinese hamster ovary cells (CHO). SCB-2019 preserves the native trimeric structure of S-protein in the prefusion form and induces neutralizing antibodies to SARS-CoV-2. Trimer-Tag is derived from the fully-human C-propeptide domain of pro-collagen and is capable of self-trimerization, thus fusing any biologically-active proteins in-frame with Trimer-Tag. The resulting fusion proteins expressed in mammalian cells are secreted as disulfide bond-linked homotrimers. The immunogenicity and safety of different dose levels (3, 9, and 30 μg) SCB-2019 vaccine, administered as 2-dose regimen 21-days apart was assessed in a phase 1 clinical study. All dose levels were well-tolerated and induced neutralizing antibodies against S protein of the SARS-CoV-2 virus. Based on the results of that study, Clover selected 30 μg of SCB-2019 in combination with the CpG 1018/alum adjuvant system for further evaluation in the phase 2/3 clinical program as having the most favorable benefit/risk profile. The pivotal study (CLO-SCB-2019-003) included approximately 30,000 healthy participants and individuals with stable pre-existing chronic medical conditions, is being conducted in multiple countries, including in Brazil. The primary purpose of that study (CLO-SCB-2019-003) is to demonstrate the safety and efficacy of SCB-2019 in the prevention of COVID-19. The study showed efficacy. Heterologous boost vaccinations using different platforms may elicit immune responses of greater magnitude and breadth than can be achieved by priming or boosting with the same vaccine (He et al, 2021, Spencer et al., 2021). Also, given the anticipated challenges of vaccinating large proportions of the population, especially with respect to supply, out-of-stock situations, and potential misadministration, it is important for policy makers to have data on flexible vaccination schedules, where the third dose might be different from the priming platform. Protein-based adjuvanted vaccines have the advantage of being from a known and licensed technology that can produce high quantities of vaccine. Protein-based adjuvanted vaccines have also been shown to be highly immunogenic, both in the context of COVID-19 (Keech 2020; Richmond 2021) and other licensed vaccines (Skwarczynski 2016). The purpose of this study is to compare the immunogenicity and safety of heterologous and homologous booster schedules in individuals who received ChAdOx1-S or CoronaVac vaccination previously. The study will be performed in 2 stages - Stage 1 will serve to down-select one of the SCB-2019 formulations for boosting. Stage 2 will compare homologous and heterologous booster regimens in individuals who have received a 2-dose primary vaccination series of either ChadOx1-S or of CoronaVac.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
520

participants targeted

Target at P75+ for phase_2 covid19

Timeline
Completed

Started Dec 2021

Shorter than P25 for phase_2 covid19

Geographic Reach
1 country

3 active sites

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

August 11, 2021

Completed
2 months until next milestone

First Posted

Study publicly available on registry

October 21, 2021

Completed
1 month until next milestone

Study Start

First participant enrolled

December 1, 2021

Completed
4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

April 1, 2022

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

April 1, 2022

Completed
Last Updated

October 21, 2021

Status Verified

October 1, 2021

Enrollment Period

4 months

First QC Date

August 11, 2021

Last Update Submit

October 19, 2021

Conditions

Keywords

Covid19ImmunogenicityVaccines

Outcome Measures

Primary Outcomes (7)

  • Immunogenicity - Stage 1

    Immunogenicity is defined as the ability of cells/tissues to provoke an immune response and is generally considered to be an undesirable physiological response, as measured by ELISA (homologous strain) and virus neutralization assay (homologous and heterologous strains).

    Day 1

  • Immunogenicity - Stage 1

    Immunogenicity is defined as the ability of cells/tissues to provoke an immune response and is generally considered to be an undesirable physiological response, as measured by ELISA (homologous strain) and virus neutralization assay (homologous and heterologous strains).

    Day 15

  • Immunogenicity - Stage 1

    Immunogenicity is defined as the ability of cells/tissues to provoke an immune response and is generally considered to be an undesirable physiological response, as measured by ELISA (homologous strain) and virus neutralization assay (homologous and heterologous strains).

    Day 29

  • Immunogenicity - Stage 2

    Immunogenicity is defined as the ability of cells/tissues to provoke an immune response and is generally considered to be an undesirable physiological response, as measured by ELISA (homologous strain) and virus neutralization assay (homologous and heterologous strains).

    Day 1

  • Immunogenicity - Stage 2

    Immunogenicity is defined as the ability of cells/tissues to provoke an immune response and is generally considered to be an undesirable physiological response, as measured by ELISA (homologous strain) and virus neutralization assay (homologous and heterologous strains).

    Day 15

  • Immunogenicity - Stage 2

    Immunogenicity is defined as the ability of cells/tissues to provoke an immune response and is generally considered to be an undesirable physiological response, as measured by ELISA (homologous strain) and virus neutralization assay (homologous and heterologous strains).

    Day 180

  • Immunogenicity - Stage 2

    Immunogenicity is defined as the ability of cells/tissues to provoke an immune response and is generally considered to be an undesirable physiological response, as measured by ELISA (homologous strain) and virus neutralization assay (homologous and heterologous strains).

    Day 360

Secondary Outcomes (2)

  • Reactogenicity

    During 7 days after study vaccination

  • Reactogenicity

    After 28 days after study vaccination

Study Arms (10)

Stage 1 - Formulation-finding for SCB-2019 - Group 1

EXPERIMENTAL

In Stage 1, immunogenicity and safety of three SCB-2019 formulations will be assessed in comparison with the ChAdOx1-S vaccine, in individuals who received two doses of ChAdOx1-S, 6 months (± 4 weeks) prior to recruitment. Participants (N=120) will be assigned to five groups for Stage 1 and receive doses as follows: Group 1: (N=30) Day 1: SCB-2019 (9 μg) alum;

Biological: Adjuvanted Recombinant SARS-CoV-2 TrimericS-protein Subunit Vaccine (SCB-2019 - Clover)

Stage 1 - Formulation-finding for SCB-2019 - Group 2

EXPERIMENTAL

In Stage 1, immunogenicity and safety of three SCB-2019 formulations will be assessed in comparison with the ChAdOx1-S vaccine, in individuals who received two doses of ChAdOx1-S, 6 months (± 4 weeks) prior to recruitment. Participants (N=120) will be assigned to five groups for Stage 1 and receive doses as follows: Group 2: (N=30) Day 1: SCB-2019 (9 μg) CpG 1018/alum;

Biological: Adjuvanted Recombinant SARS-CoV-2 TrimericS-protein Subunit Vaccine (SCB-2019 - Clover)

Stage 1 - Formulation-finding for SCB-2019 - Group 3

EXPERIMENTAL

In Stage 1, immunogenicity and safety of three SCB-2019 formulations will be assessed in comparison with the ChAdOx1-S vaccine, in individuals who received two doses of ChAdOx1-S, 6 months (± 4 weeks) prior to recruitment. Participants (N=120) will be assigned to five groups for Stage 1 and receive doses as follows: Group 3: (N=30) Day 1: SCB-2019 (30 μg) CpG 1018/alum;

Biological: Adjuvanted Recombinant SARS-CoV-2 TrimericS-protein Subunit Vaccine (SCB-2019 - Clover)

Stage 1 - Formulation-finding for SCB-2019 - Group 4

EXPERIMENTAL

In Stage 1, immunogenicity and safety of three SCB-2019 formulations will be assessed in comparison with the ChAdOx1-S vaccine, in individuals who received two doses of ChAdOx1-S, 6 months (± 4 weeks) prior to recruitment. Participants (N=120) will be assigned to five groups for Stage 1 and receive doses as follows: Group 4: (N=30) Day 1: ChAdOx1-S;

Biological: ChAdOx1-S COVID-19 Vaccine(Fiocruz/Oxford-AstraZeneca)

Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 5

EXPERIMENTAL

For Stage 2, immunogenicity of heterologous booster vaccination schedule (ChAdOx1-S (Group 5-7) - selected formulation of SCB-2019 or CoronaVac and CoronaVac (Group 8-10) - selected formulation of SCB-2019 or ChAdOx1) vs. a 2-dose ChAdOx1-S or CoronaVac series will be assessed. Participants (N=400) will be randomly (2:1:1) distributed into 6 groups for Stage 2 and receive doses as follows: Group 5: (N=100) Day 1 (boost) -SCB-2019;

Biological: Adjuvanted Recombinant SARS-CoV-2 TrimericS-protein Subunit Vaccine (SCB-2019 - Clover)

Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 6

EXPERIMENTAL

For Stage 2, immunogenicity of heterologous booster vaccination schedule (ChAdOx1-S (Group 5-7) - selected formulation of SCB-2019 or CoronaVac and CoronaVac (Group 8-10) - selected formulation of SCB-2019 or ChAdOx1) vs. a 2-dose ChAdOx1-S or CoronaVac series will be assessed. Participants (N=400) will be randomly (2:1:1) distributed into 6 groups for Stage 2 and receive doses as follows: Group 6: (N=50) Day 1 (boost) -ChAdOx1-S;

Biological: ChAdOx1-S COVID-19 Vaccine(Fiocruz/Oxford-AstraZeneca)

Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 7

EXPERIMENTAL

For Stage 2, immunogenicity of heterologous booster vaccination schedule (ChAdOx1-S (Group 5-7) - selected formulation of SCB-2019 or CoronaVac and CoronaVac (Group 8-10) - selected formulation of SCB-2019 or ChAdOx1) vs. a 2-dose ChAdOx1-S or CoronaVac series will be assessed. Participants (N=400) will be randomly (2:1:1) distributed into 6 groups for Stage 2 and receive doses as follows: Group 7: (N=50) Day 1 (boost) -CoronaVac;

Biological: CoronaVac (Sinovac Biotech)

Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 8

EXPERIMENTAL

For Stage 2, immunogenicity of heterologous booster vaccination schedule (ChAdOx1-S (Group 5-7) - selected formulation of SCB-2019 or CoronaVac and CoronaVac (Group 8-10) - selected formulation of SCB-2019 or ChAdOx1) vs. a 2-dose ChAdOx1-S or CoronaVac series will be assessed. Participants (N=400) will be randomly (2:1:1) distributed into 6 groups for Stage 2 and receive doses as follows: Group 8: (N=100) Day 1 (boost) -SCB-2019;

Biological: Adjuvanted Recombinant SARS-CoV-2 TrimericS-protein Subunit Vaccine (SCB-2019 - Clover)

Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 9

EXPERIMENTAL

For Stage 2, immunogenicity of heterologous booster vaccination schedule (ChAdOx1-S (Group 5-7) - selected formulation of SCB-2019 or CoronaVac and CoronaVac (Group 8-10) - selected formulation of SCB-2019 or ChAdOx1) vs. a 2-dose ChAdOx1-S or CoronaVac series will be assessed. Participants (N=400) will be randomly (2:1:1) distributed into 6 groups for Stage 2 and receive doses as follows: Group 9: (N=50) Day 1 (boost) - ChAdOx1-S;

Biological: ChAdOx1-S COVID-19 Vaccine(Fiocruz/Oxford-AstraZeneca)

Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 10

EXPERIMENTAL

For Stage 2, immunogenicity of heterologous booster vaccination schedule (ChAdOx1-S (Group 5-7) - selected formulation of SCB-2019 or CoronaVac and CoronaVac (Group 8-10) - selected formulation of SCB-2019 or ChAdOx1) vs. a 2-dose ChAdOx1-S or CoronaVac series will be assessed. Participants (N=400) will be randomly (2:1:1) distributed into 6 groups for Stage 2 and receive doses as follows: Group 10: (N=50) Day 1 (boost) - CoronaVac.

Biological: CoronaVac (Sinovac Biotech)

Interventions

Heterologous and Homologous Vaccination Series with ChAdOx1-S or CoronaVac COVID-19 Vaccines and Various Formulations of Clover Adjuvanted Recombinant SARS-CoV-2 Trimeric S-protein Subunit Vaccine (SCB-2019) in Adults

Stage 1 - Formulation-finding for SCB-2019 - Group 4Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 6Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 9

Heterologous and Homologous Vaccination Series with ChAdOx1-S or CoronaVac COVID-19 Vaccines and Various Formulations of Clover Adjuvanted Recombinant SARS-CoV-2 Trimeric S-protein Subunit Vaccine (SCB-2019) in Adults

Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 10Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 7

Heterologous and Homologous Vaccination Series with ChAdOx1-S or CoronaVac COVID-19 Vaccines and Various Formulations of Clover Adjuvanted Recombinant SARS-CoV-2 Trimeric S-protein Subunit Vaccine (SCB-2019) in Adults

Stage 1 - Formulation-finding for SCB-2019 - Group 1Stage 1 - Formulation-finding for SCB-2019 - Group 2Stage 1 - Formulation-finding for SCB-2019 - Group 3Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 5Stage 2 - Homologous vs. Heterologous Booster Regimen - Group 8

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Male or female ≥18 years of age.
  • Individuals are willing and able to comply with study requirements, including all scheduled visits, vaccinations, laboratory tests, and other study procedures.
  • Individuals are willing and able to give an informed consent, prior to screening.
  • Individuals who:
  • Received two dose of ChAdOx1-S vaccine 6 months (± 4 weeks) (Groups 1-4 of Stage 1 and Groups 5-7 of Stage 2) or CoronaVac 6 months (± 4 weeks) (Groups 8-10 of Stage 2) prior to recruitment in this study
  • Healthy participants or participants with pre-existing medical conditions who are in a stable medical condition. A stable medical condition is defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 3 months before enrollment.
  • Female participants are eligible to participate in the study if not pregnant, not breastfeeding, and at least 1 of the following criteria apply:
  • Women of non-childbearing potential;
  • Women of childbearing potential (WOCBP) must have a negative urine pregnancy test prior to study vaccination. A confirmatory serum pregnancy test may be conducted at the investigator's discretion. They must be using a highly effective licensed method of birth control for 30 days prior to the first vaccination and must agree to continue such precautions during the study until 90 days after the last study vaccination.
  • Male participants must agree to employ acceptable contraception from the day of first dose of the study vaccine/comparator until 6 months after the last dose of the study vaccine/comparator and also refrain from donating sperm during this period.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (3)

Hospital de Clínicas de Porto Alegre

Porto Alegre, Rio de Grande Do Sul, Brazil

Location

Hospital Gloria D'or

Rio de Janeiro, Rio de, Brazil

Location

Centro de Estudos e Pesquisa em Moléstias Infecciosas (CEPCLIN)

Natal, Rio Grande do Norte, Brazil

Location

Related Publications (1)

  • Costa Clemens SA, Milan EP, Sprinz E, Neto JC, Pacciarini F, Li P, Chen HL, Smolenov I, Pollard A, Clemens R. Homologous and Heterologous Boosting of the Chadox1-S1-S COVID-19 Vaccine With the SCB-2019 Vaccine Candidate: A Randomized, Controlled, Phase 2 Study. Open Forum Infect Dis. 2022 Aug 16;9(8):ofac418. doi: 10.1093/ofid/ofac418. eCollection 2022 Aug.

MeSH Terms

Conditions

COVID-19

Interventions

sinovac COVID-19 vaccine

Condition Hierarchy (Ancestors)

Pneumonia, ViralPneumoniaRespiratory Tract InfectionsInfectionsVirus DiseasesCoronavirus InfectionsCoronaviridae InfectionsNidovirales InfectionsRNA Virus InfectionsLung DiseasesRespiratory Tract Diseases

Study Officials

  • Sue Ann Clemens Costa Clemens, MD, PhD

    Global Health - Oxford University Siena University

    STUDY DIRECTOR

Central Study Contacts

Eveline Pipolo Milan, MD

CONTACT

Study Design

Study Type
interventional
Phase
phase 2
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Masking Details
This study will be observer-blind for Stage 1 and Stage 2. The participants will be blinded before receiving the study vaccination. An unblinded dosing team, not involved with study participant's evaluation, will prepare and administer the study vaccines. The investigational product syringe will be opacified. The administration of the study vaccine will also be performed behind a closed curtain. The investigative study center personnel, as well as the sponsor personnel involved in the monitoring or conduct of the study, will be blinded to the study vaccine code. The laboratories will also be blinded, so that associating the sample with an assigned treatment or study visit will not be possible.
Purpose
PREVENTION
Intervention Model
PARALLEL
Model Details: Controlled, observer-blinded, Phase 2 Study
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 11, 2021

First Posted

October 21, 2021

Study Start

December 1, 2021

Primary Completion

April 1, 2022

Study Completion

April 1, 2022

Last Updated

October 21, 2021

Record last verified: 2021-10

Data Sharing

IPD Sharing
Will not share

Locations