A Study on the Safety and Immune Response of Investigational COVID-19 mRNA Vaccines in Healthy Adults

NCT ID: NCT05960097

Last Updated: 2025-10-23

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2
• Total Enrollment: 692 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-08-01
• Study Completion Date: 2024-08-30

Brief Summary

The purpose of Part A of this study is to assess the immune response and safety of a booster dose of investigational COVID-19 mRNA vaccines in healthy adults. The study will compare the investigational vaccines to control vaccine.

The purpose of Part B of this study is to assess the immune response and safety of a booster dose of investigational COVID-19 mRNA vaccines in healthy adults. The study will compare the investigational vaccine under three different storage conditions.

Detailed Description

Part A:

This Phase 2 study's Part A evaluates the safety, reactogenicity, and immunogenicity of two candidate vaccines - the bivalent CV0701 and the monovalent CV0601 - in healthy adults who have received a full primary vaccination series (with or without booster doses). By including these candidates, the study will assess whether immune interference occurs between the XY spike protein and the XX spike protein antigens in the bivalent vaccine compared with the XX spike protein antigen in the monovalent vaccine. In Part A, both CV0701 and CV0601 will be compared to the Control Vaccine (that serve as a standard of care control) using a randomized, observer-blinded design.

Part B:

The purpose of Part B is to evaluate the safety and Day 29 immunogenicity of CV0801 under three storage conditions:

• Condition 1: Baseline/control
• Condition 2: Intermediate storage
• Condition 3: Maximum storage

Condition 1 serves as the control against which the performance (safety, reactogenicity, and immunogenicity) of Conditions 2 and 3 will be compared.

mRNA vaccine stability is affected by product-specific factors (e.g., molecular weight, buffer composition, lipid nanoparticle encapsulation), manufacturing factors (such as the duration the vaccine remains in liquid form during production and handling at different temperatures), and storage conditions. The impact of these factors is based on product and process knowledge as well as clinical experience.

Through Part B of this Phase 2 study, GSK and CureVac aim to develop data on how different storage conditions affect the final attributes of the vaccine in a clinical trial setting.

Conditions

SARS-CoV-2; COVID-19

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: TRIPLE

Study Groups

Part A: CV0701 mRNA COVID-19 Vaccine (Low dose)

Participants received one dose of the CV0701 mRNA COVID-19 vaccine in the low-dose formulation on Day 1.

Group Type: EXPERIMENTAL

CV0701 mRNA COVID-19 Vaccine (Low dose)

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: CV0701 mRNA COVID-19 Vaccine (Medium dose)

Participants received one dose of the CV0701 mRNA COVID-19 vaccine in the medium-dose formulation on Day 1.

Group Type: EXPERIMENTAL

CV0701 mRNA COVID-19 Vaccine (Medium dose)

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: CV0701 mRNA COVID-19 Vaccine (High dose)

Participants received one dose of the CV0701 mRNA COVID-19 vaccine in the high-dose formulation on Day 1.

Group Type: EXPERIMENTAL

CV0701 mRNA COVID-19 Vaccine (High dose)

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: CV0601 mRNA COVID-19 vaccine

Participants received one dose of the CV0601 mRNA COVID-19 vaccine on Day 1.

Group Type: EXPERIMENTAL

CV0601 mRNA COVID-19 Vaccine

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part A: Control Vaccine

Participants received one dose of the control vaccine at Day 1.

Group Type: ACTIVE_COMPARATOR

Control vaccine

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part B: CV0801 mRNA COVID-19 vaccine (Maximum storage condition)

Participants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Maximum storage condition.

Group Type: EXPERIMENTAL

CV0801 mRNA COVID-19 Vaccine

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part B: CV0801 mRNA COVID-19 vaccine (Intermediate storage condition)

Participants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Intermediate storage condition.

Group Type: EXPERIMENTAL

CV0801 mRNA COVID-19 Vaccine

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Part B: CV0801 mRNA COVID-19 vaccine (Baseline-control storage condition)

Participants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Baseline-control storage condition.

Group Type: EXPERIMENTAL

CV0801 mRNA COVID-19 Vaccine

Intervention Type: BIOLOGICAL

Study vaccine was administered as a single intramuscular injection.

Interventions

CV0701 mRNA COVID-19 Vaccine (Low dose)

Study vaccine was administered as a single intramuscular injection.

Intervention Type: BIOLOGICAL

CV0701 mRNA COVID-19 Vaccine (Medium dose)

Study vaccine was administered as a single intramuscular injection.

Intervention Type: BIOLOGICAL

CV0701 mRNA COVID-19 Vaccine (High dose)

Study vaccine was administered as a single intramuscular injection.

Intervention Type: BIOLOGICAL

CV0601 mRNA COVID-19 Vaccine

Study vaccine was administered as a single intramuscular injection.

Intervention Type: BIOLOGICAL

Control vaccine

Study vaccine was administered as a single intramuscular injection.

Intervention Type: BIOLOGICAL

CV0801 mRNA COVID-19 Vaccine

Study vaccine was administered as a single intramuscular injection.

Intervention Type: BIOLOGICAL

Eligibility Criteria

Inclusion Criteria

1. Is at least 18 years old and has achieved legal age according to local regulations in each participating country.

2. Must provide documented informed consent prior to any study procedures being performed.

3. Can and will comply with the requirements of the protocol, in the opinion of the investigator.

4. Is healthy or medically stable as determined by the investigator's judgment based on medical history, vital sign measurements, and physical examination findings. Participants with pre-existing stable disease, defined as disease not requiring significant change in therapy or hospitalization for worsening disease during the 6 weeks before enrollment, can be included.

5. Prior receipt of an mRNA COVID-19 vaccine. This may be from a completed primary vaccination series or booster dose(s) of an approved or authorized mRNA COVID-19 vaccine. The last vaccination must be an mRNA COVID-19 vaccination received at least 3 months prior to randomization.

6. If the participant is a woman of childbearing potential, the participant may be enrolled in the study, if they:

• have practiced adequate contraception for 30 days prior to study intervention administration; and
• have a negative pregnancy test result on the day of study intervention administration; and
• have agreed to continue adequate contraception for 2 months after study intervention administration.

Female participants of non-childbearing potential may be enrolled in the study. Nonchildbearing potential is defined as current salpingectomy, hysterectomy, ovariectomy, or postmenopausal.

Participants are excluded from the study if any of the following criteria apply:

1. Is pregnant or has a positive pregnancy test result at Visit 1.

2. Is breastfeeding or will (re)start breastfeeding from the study intervention administration to 3 months after study intervention administration.

3. Has any medical disease or psychiatric condition that, in the opinion of the investigator, precludes study participation because it would place the participant at an unacceptable risk of injury, would render them unable to meet the requirements of the protocol or may interfere with successful completion of the study.

4. Has any history of an immunosuppressive or immunodeficient condition resulting from disease.

5. Has used immunosuppressants or other immune-modifying drugs for 14 consecutive days or more within 3 months prior to the study intervention administration. Non-systemic corticosteroids are allowed. If systemic corticosteroids have been administered short term (<14 days) for treatment of an acute illness, participants should not be enrolled into the study until corticosteroid therapy has been discontinued for at least 28 days before study intervention administration.

6. Has an acute medical illness or acute febrile illness with oral temperature ≥38.0°C or ≥100.4°F within 72 hours prior to study intervention administration.

7. Has participated in another study involving any investigational product, vaccine, or device within 28 days before the study intervention administration and/or planned participation through end of study (EoS).

8. Has participated in Part A of this study.

9. Has a history of hypersensitivity or severe allergic reaction including anaphylaxis, generalized urticaria, angioedema, and other significant reactions to any previous mRNA vaccine or any component of the study intervention(s).

10. Has received or plans to receive immunoglobulins or any blood or blood products within 3 months before study intervention administration through EoS.

11. Has a bleeding disorder, or prior history of significant bleeding or bruising following intramuscular injections.

12. Has a history of chronic alcohol consumption and/or drug abuse as deemed by the investigator to render the potential participant unable/unlikely to provide accurate safety reports or comply with study procedures.

13. Has a history of myocarditis, pericarditis, or idiopathic cardiomyopathy, or presence of any medical condition that increases risk of myocarditis or pericarditis, including cocaine abuse, cardiomyopathy, endomyocardial fibrosis, hypereosinophilic syndrome, hypersensitivity myocarditis, eosinophilic granulomatosis with polyangiitis and persistent myocardial infection.

14. Has received a live vaccine 30 days before the study intervention administration or has a planned administration within 30 days after the study intervention administration.

15. Has received a non-replicating vaccine 8 days before the study intervention administration or has a planned administration within 14 days after the study intervention administration.

16. Has a documented history of confirmed SARS-CoV-2 infection within 3 months before study intervention administration.

17. Has had known close contact with anyone who had a confirmed SARS-CoV-2 infection within 2 weeks before study intervention administration.

18. Is an employee or family member of the investigator or study site staff.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

CureVac

INDUSTRY

Sponsor Role: collaborator

GlaxoSmithKline

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

GSK Investigational Site

Sacramento, California, United States

GSK Investigational Site

Hollywood, Florida, United States

GSK Investigational Site

Peoria, Illinois, United States

GSK Investigational Site

Bruce, Australian Capital Territory, Australia

GSK Investigational Site

Blacktown, New South Wales, Australia

GSK Investigational Site

Botany, New South Wales, Australia

GSK Investigational Site

Brookvale, New South Wales, Australia

GSK Investigational Site

Coffs Harbour, New South Wales, Australia

GSK Investigational Site

Darlinghurst, New South Wales, Australia

GSK Investigational Site

Kanwal, New South Wales, Australia

GSK Investigational Site

Maroubra, New South Wales, Australia

GSK Investigational Site

Merewether, New South Wales, Australia

GSK Investigational Site

Blacktown, Queensland, Australia

GSK Investigational Site

Sherwood, Queensland, Australia

GSK Investigational Site

Tarragindi, Queensland, Australia

GSK Investigational Site

Adelaide, South Australia, Australia

GSK Investigational Site

Camberwell, Victoria, Australia

Countries

United States; Australia

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

219075

Identifier Type: -

Identifier Source: org_study_id