AzTrials
AzTrials

SARS-CoV-2Phase 2NCT05960097

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

A Phase 2 study testing CV0701 mRNA COVID-19 Vaccine (Low dose), CV0701 mRNA COVID-19 Vaccine (Medium dose) and CV0701 mRNA COVID-19 Vaccine (High dose) in people with SARS-CoV-2 and COVID-19, run by GlaxoSmithKline at 17 sites in 2 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial 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. Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
SARS-CoV-2, COVID-19
What is being tested?
CV0701 mRNA COVID-19 Vaccine (Low dose), CV0701 mRNA COVID-19 Vaccine (Medium dose) and CV0701 mRNA COVID-19 Vaccine (High dose)
Could I receive a placebo?
No, everyone receives an active treatment
How many people
692 participants
Where
17 sitesin 2 countries
Study dates
1 Aug 2023to 30 Aug 2024
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Participants are eligible to be included in the study only if all of the following criteria apply:

  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.

Trial locations and contacts

17 sites in 2 countries.

17 sites in 2 countries

Australia14 sites

  • GSK Investigational Site

    Adelaide, South Australia, 5000

  • GSK Investigational Site

    Blacktown, New South Wales, 2148

  • GSK Investigational Site

    Blacktown, Queensland, 4006

  • GSK Investigational Site

    Botany, New South Wales, 2019

  • GSK Investigational Site

    Brookvale, New South Wales, 2100

  • GSK Investigational Site

    Bruce, Australian Capital Territory, 2617

  • GSK Investigational Site

    Camberwell, Victoria, 3124

  • GSK Investigational Site

    Coffs Harbour, New South Wales, 2450

  • GSK Investigational Site

    Darlinghurst, New South Wales, 2010

  • GSK Investigational Site

    Kanwal, New South Wales, 2259

  • GSK Investigational Site

    Maroubra, New South Wales, 2035

  • GSK Investigational Site

    Merewether, New South Wales, 2291

  • GSK Investigational Site

    Sherwood, Queensland, 4068

  • GSK Investigational Site

    Tarragindi, Queensland, 4075

Other trials in Australia

United States3 sites

  • GSK Investigational Site

    Hollywood, Florida, 33024

  • GSK Investigational Site

    Peoria, Illinois, 61614-4896

  • GSK Investigational Site

    Sacramento, California, 95864

Other trials in United States

About this study

Official title: A Phase 2 Randomized, Active-controlled, Observer-blind Study to Assess the Safety, Reactogenicity, and Immunogenicity of a Booster Dose of Investigational COVID-19 mRNA Vaccines in Healthy Adults Who Previously Received a Complete Primary Vaccination Series With or Without Booster Dose(s)

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.

Read the 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
Being tested
CV0701 mRNA COVID-19 Vaccine (Low dose), CV0701 mRNA COVID-19 Vaccine (Medium dose), CV0701 mRNA COVID-19 Vaccine (High dose), CV0601 mRNA COVID-19 Vaccine, Control vaccine
Keywords
COVID-19, Pandemic, Booster vaccine
Medical subject headings
COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • CV0701 mRNA COVID-19 Vaccine (Low dose)Biological

    Study vaccine was administered as a single intramuscular injection.

  • CV0701 mRNA COVID-19 Vaccine (Medium dose)Biological

    Study vaccine was administered as a single intramuscular injection.

  • CV0701 mRNA COVID-19 Vaccine (High dose)Biological

    Study vaccine was administered as a single intramuscular injection.

  • CV0601 mRNA COVID-19 VaccineBiological

    Study vaccine was administered as a single intramuscular injection.

  • Control vaccineBiological

    Study vaccine was administered as a single intramuscular injection.

  • CV0801 mRNA COVID-19 VaccineBiological

    Study vaccine was administered as a single intramuscular injection.

Study groups in NCT05960097
Study groupRoleWhat they receive
Part A: CV0701 mRNA COVID-19 Vaccine (Low dose)ExperimentalParticipants received one dose of the CV0701 mRNA COVID-19 vaccine in the low-dose formulation on Day 1.
Receives: Biological: CV0701 mRNA COVID-19 Vaccine (Low dose)
Part A: CV0701 mRNA COVID-19 Vaccine (Medium dose)ExperimentalParticipants received one dose of the CV0701 mRNA COVID-19 vaccine in the medium-dose formulation on Day 1.
Receives: Biological: CV0701 mRNA COVID-19 Vaccine (Medium dose)
Part A: CV0701 mRNA COVID-19 Vaccine (High dose)ExperimentalParticipants received one dose of the CV0701 mRNA COVID-19 vaccine in the high-dose formulation on Day 1.
Receives: Biological: CV0701 mRNA COVID-19 Vaccine (High dose)
Part A: CV0601 mRNA COVID-19 vaccineExperimentalParticipants received one dose of the CV0601 mRNA COVID-19 vaccine on Day 1.
Receives: Biological: CV0601 mRNA COVID-19 Vaccine
Part A: Control VaccineActive comparatorParticipants received one dose of the control vaccine at Day 1.
Receives: Biological: Control vaccine
Part B: CV0801 mRNA COVID-19 vaccine (Maximum storage condition)ExperimentalParticipants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Maximum storage condition.
Receives: Biological: CV0801 mRNA COVID-19 Vaccine
Part B: CV0801 mRNA COVID-19 vaccine (Intermediate storage condition)ExperimentalParticipants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Intermediate storage condition.
Receives: Biological: CV0801 mRNA COVID-19 Vaccine
Part B: CV0801 mRNA COVID-19 vaccine (Baseline-control storage condition)ExperimentalParticipants received one dose of the CV0801 mRNA COVID-19 vaccine on Day 1 under Baseline-control storage condition.
Receives: Biological: CV0801 mRNA COVID-19 Vaccine

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Part A: Geometric Mean Titer (GMT) of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein

    Measured: At Day 29

  2. Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

    Measured: At Day 29

  3. Part B: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

    Measured: At Day 29

  4. Part A: Number of Participants Reporting Any Solicited Administration Site Adverse Events (AEs)

    Assessed solicited administration site events included injection site redness (erythema), pain, swelling and lymphadenopathy (defined as localized axillary, cervical or supraclavicular swelling or tenderness ipsilateral to the injection arm). Any = occurrence of the event regardless of intensity grade.

    Measured: Day 1 to Day 7

  5. Part A: Number of Participants Reporting Any Solicited Systemic AEs

    Assessed solicited systemic events included fever, chills, headache, myalgia (muscle pain), arthralgia (joint pain), and fatigue (tiredness). Fever is defined as body temperature is higher than or equal to (>=) 38ºC; preferred location for measuring the temperature is oral. Any = occurrence of the event regardless of intensity grade.

    Measured: Day 1 to Day 7

  6. Part A: Number of Participants Reporting Any Unsolicited AEs

    An unsolicited AE is an AE that is either not included in the list of solicited events or can be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events. Unsolicited AEs include both serious and nonserious AEs. Any = occurrence of the event regardless of intensity grade.

    Measured: Day 1 to Day 28

  7. Part A: Number of Participants Reporting Any Medically Attended Adverse Events (MAAEs), Serious Adverse Events (SAEs) and AEs of Special Interest (AESIs)

    An SAE refers to any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or extends existing hospitalization, causes persistent or significant disability/incapacity, involves a congenital anomaly/birth defect in a participant's offspring, includes an abnormal pregnancy outcome, or occurs in any other situation per the investigator's judgement.

    An MAAE results in a visit to a medical professional, such as televisits, physician's office visits, urgent care visits, emergency rooms visits, or hospitalizations.

    AESIs are severe or non-severe predefined AEs of scientific and medical concern specific to the product/program. This study noted the following AESIs: potential immune-mediated disease (pIMDs), lab-confirmed moderate to severe COVID-19, myocarditis and pericarditis, anaphylaxis, or severe hypersensitivity within 24 hours post-intervention. "Any" indicates the occurrence of the event regardless of its intensity grade.

    Measured: Day 1 to Day 181

  8. Part B: Number of Participants Reporting Any Solicited Administration Site AEs

    Assessed solicited administration site events included injection site redness (erythema), pain, swelling and lymphadenopathy (defined as localized axillary, cervical or supraclavicular swelling or tenderness ipsilateral to the injection arm). Any = occurrence of the event regardless of intensity grade.

    Measured: Day 1 to Day 7

  9. Part B: Number of Participants Reporting Any Solicited Systemic AEs

    Assessed solicited systemic events included fever, chills, headache, myalgia (muscle pain), arthralgia (joint pain), and fatigue (tiredness). Fever is defined as body temperature >= 38ºC; preferred location for measuring the temperature is oral. Any = occurrence of the event regardless of intensity grade.

    Measured: Day 1 to Day 7

  10. Part B: Number of Participants Reporting Any Unsolicited AEs

    An unsolicited AE is an AE that is either not included in the list of solicited events or can be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events. Unsolicited AEs include both serious and nonserious AEs. Any = occurrence of the event regardless of intensity grade.

    Measured: Day 1 to Day 28

  11. Part B: Number of Participants Reporting Any MAAEs, SAEs and AESIs

    Measured: Day 1 to Day 181

Secondary outcomes (9)

  1. Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein

    Measured: At Day 91 and Day 181

  2. Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

    Measured: At Day 91 and Day 181

  3. Part A: GMT of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XZ Spike Protein

    Measured: At Day 29, Day 91 and Day 181

  4. Part A: Percentage of Participants With Seroresponse of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein

    Seroresponse is defined as post-booster titer greater than or equal to (≥) 4 times the lower limit of quantification (LLOQ) when pre-vaccination titer is below LLOQ or a post-booster titer ≥ 4 times the pre-booster titer when pre-vaccination titer is ≥ LLOQ.

    Measured: At Day 29 compared to baseline (Day 1)

  5. Part A: Percentage of Participants With Seroresponse of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

    Seroresponse is defined as post-booster titer ≥ 4 times the lower limit of quantification (LLOQ) when pre-vaccination titer is below LLOQ or a post-booster titer ≥ 4 times the pre-booster titer when pre-vaccination titer is ≥ LLOQ.

    Measured: At Day 29 compared to baseline (Day 1)

  6. Part A: Percentage of Participants With Seroresponse of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XZ Spike Protein

    Seroresponse is defined as post-booster titer ≥ 4 times the LLOQ when pre-vaccination titer is below LLOQ or a post-booster titer ≥ 4 times the pre-booster titer when pre-vaccination titer is ≥ LLOQ.

    Measured: At Day 29 compared to baseline (Day 1)

  7. Part A: Geometric Mean Increase (GMI) of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein

    GMI is defined as the the geometric mean of the within participant ratios of the post-dose titer over the pre-dose titer.

    Measured: At Day 29, Day 91 and Day 181 compared to baseline (Day 1)

  8. Part A: GMI of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XY Spike Protein

    GMI is defined as the the geometric mean of the within participant ratios of the post-dose titer over the pre-dose titer.

    Measured: At Day 29, Day 91 and Day 181 compared to baseline (Day 1)

  9. Part A: GMI of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XZ Spike Protein

    GMI is defined as the the geometric mean of the within participant ratios of the post-dose titer over the pre-dose titer.

    Measured: At Day 29, Day 91 and Day 181 compared to baseline (Day 1)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Jul 2023
  2. Study start1 Aug 2023
  3. Primary completion30 Aug 2024
  4. Study completion30 Aug 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
692 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05960097
Sponsor's protocol ID
219075
Status last verified
Oct 2025
First submitted
24 Jul 2023
Last updated
23 Oct 2025
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Qualified researchers may request access to anonymized individual patient-level data (IPD) and related study documents of the eligible studies via the Data Sharing Portal. Details on GSK's data sharing criteria can be found at: https://www.gsk.com/en-gb/innovation/trials/data-transparency/

Publications

  • Wong R, Kuznetsova A, Baba E, Ganyani T, Berre S, Boutet P, Ramanathan R, Douglas D, Mann P, Gaudinski MR. Safety and immunogenicity of an mRNA COVID-19 vaccine administered to adults: A phase 2, randomized, active-controlled trial. Hum Vaccin Immunother. 2026 Dec;22(1):2715900. doi: 10.1080/21645515.2026.2715900. Epub 2026 Aug 26.

    PubMed 42647564

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing CV0701 mRNA COVID-19 Vaccine (Low dose), CV0701 mRNA COVID-19 Vaccine (Medium dose) and CV0701 mRNA COVID-19 Vaccine (High dose) in people with SARS-CoV-2 and COVID-19, run by GlaxoSmithKline at 17 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 23 Oct 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 17 sites in Australia, United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 23 Oct 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Part A: Geometric Mean Titer (GMT) of Serum Neutralization Titers Against Pseudovirus Bearing SARS-CoV-2 Strain XX Spike Protein (time frame: At Day 29). The study lists 11 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05960097, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Oct 2025.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in