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Recruiting

NCT Number: NCT07464314

A Study on the Safety and Immune Response of Investigational mRNA Seasonal Flu/COVID-19 Combination Vaccine in Adults

This early-stage study will look at a new mRNA vaccine that combines defenses against both seasonal flu and COVID-19 in terms of its safety and how it builds protection. Healthy adults aged 65 to 85 will receive different doses of this new vaccine, a standard flu vaccine, or COVID-19 vaccine. The study will assess any side effects or health issues, and additional blood samples will be collected at specific times to evaluate how well participants bodies build protection against the flu and COVID-19.

Recruiting

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Key information

Age range

65 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 1

Primary location

GSK Investigational Site, Anniston, Alabama, United States

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participants, who, in the opinion of the investigator, can and will comply with the requirements of the protocol independently or with the assistance of the caregiver.
  • Informed consent obtained from the participant prior to performance of any study-specific procedure.
  • A male or female 65 to 85 years of age (YoA) (inclusive) at the time of screening.
  • Healthy participants or medically stable patients as established by medical history and clinical examination.
  • Other protocol-defined inclusion criteria may apply.

Exclusion criteria

  • Any clinically significant laboratory abnormality.
  • History of symptomatic influenza/ SARS-CoV-2 infection confirmed by local health authority-approved testing methods within 180 days (for influenza) or 90 days (SARS-CoV-2 infection) prior to study intervention administration.
  • History of Guillain-Barré syndrome (GBS) within 6 weeks of receiving any vaccine.
  • Current or past malignancy, unless completely resolved without clinically significant sequelae (e.g., no evidence of disease following successful treatment of basal cell carcinoma cases are allowed) for >5 years.
  • Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
  • History of or current suspicion of myocarditis or pericarditis (including following administration of an mRNA vaccine); or idiopathic cardiomyopathy, or presence of any medical condition that increases the risk of myocarditis or pericarditis, including cocaine abuse, cardiomyopathy, endomyocardial fibrosis, hypereosinophilic syndrome, hypersensitivity myocarditis, eosinophilic granulomatosis with polyangiitis and persistent myocardial infection.
  • History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention(s).
  • Acute or unstable chronic conditions, clinically significant pulmonary, cardiovascular, or renal functional abnormality, as determined by physical examination and/or laboratory screening tests.
  • History of hypersensitivity or allergic reaction to any previous influenza or COVID-19 vaccine.
  • History of hypersensitivity or allergic reaction to any previous mRNA vaccine.
  • Administration of any influenza vaccine within 181 days before the study intervention administration (Day -180 to Day 1) or planned administration within 28 days (Day 29) after the study intervention administration.
  • Administration of a SARS-CoV-2 antigen-containing vaccine in the period starting 91 days before the study intervention administration (Day -90 to Day 1) or planned administration within 28 days (Day 29) after the study intervention administration.
  • Administration of any mRNA-based vaccine in the period starting 29 days before the study intervention administration (Day -28 to Day 1) or planned administration within 28 days (Day 29) after the study intervention administration.
  • Administration of any other vaccine not foreseen by the study protocol in the period starting 29 days (Day -28 to Day 1) before the study intervention administration or planned administration within 28 days (Day 29) after the study intervention administration.
  • Other protocol-defined exclusion criteria may apply.

Treatment and study plan

Investigational mRNA Seasonal Flu/COVID-19 Combination (Flu/COVm) Vaccine

Biological

Flu/COVm Vaccine with multiple dose levels (Dose Level 1, Dose Level 2, and Dose Level 3), will be administered via single intramuscular injection.

Licensed Seasonal Influenza Vaccine

Biological

License Seasonal Influenza Vaccine will be administered as a single intramuscular dose.

Licensed COVID-19 Vaccine

Biological

Licensed COVID-19 Vaccine will be administered as a single intramuscular dose.

Primary outcomes

  1. Number of Participants with an Increase in Toxicity Grade of Laboratory Value Abnormalities Following Administration of the Study Intervention

    Time frame: Day 1 to Day 3

    The assessed toxicity grades for laboratory value abnormalities will be defined as follows: Grade 1 = Mild, Grade 2 = Moderate, Grade 3 = Severe, and Grade 4 = Potentially life-threatening.

  2. Number of Participants with an Increase in Toxicity Grade of Laboratory Value Abnormalities following Administration of Study Intervention

    Time frame: Day 1 to Day 8

  3. Number of Participants with an Increase in Toxicity Grade of Laboratory Value Abnormalities following Administration of Study Intervention

    Time frame: Day 1 to Day 29

  4. Number of Participants with Solicited Administration Site Adverse Events (AEs)

    Time frame: Day 1 to Day 7

    The solicited administration site AEs considered are pain, redness, swelling and lymphadenopathy.

  5. Number of Participants with Solicited Systemic AEs

    Time frame: Day 1 to Day 7

    The solicited systemic AEs considered are fever, headache, fatigue, myalgia, arthralgia and chills.

  6. Number of Participants with Unsolicited AEs

    Time frame: Day 1 to Day 28

    An unsolicited AE is an AE that was either not included in the list of solicited events or could be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events.

  7. Number of Participants with Serious Adverse Events (SAEs)

    Time frame: Day 1 to Day 181

    A SAE is an AE which results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in disability/incapacity, or other situations that are considered serious per medical or scientific judgment.

  8. Number of Participants with Adverse Events of Special Interest (AESIs)

    Time frame: Day 1 to Day 181

    The following events are considered as AESI in this study: severe hypersensitivity reactions within 24 hours after study intervention administration, Aminotransferase elevation; myocarditis/pericarditis within 6 weeks after study intervention administration and potential immune-mediated diseases (pIMDs).

  9. Number of Participants with Medically Attended Adverse Events (MAAEs)

    Time frame: Day 1 to Day 181

    A MAAE is an AE for which the participant received medical attention including any symptom or illness requiring hospitalization, or an emergency room visit, or visit to/by a healthcare professional.

Secondary outcomes

  1. Geometric Mean Titer (GMT) Of Antigen 1 Titer

    Time frame: At Day 29

  2. Percentage of Participants with Antigen 1 Seroconversion Rate (SCR)

    Time frame: Day 1 to Day 29

  3. Percentage of Participants with Antigen 1 Seroprotection Rate (SPR)

    Time frame: At Day 1 and Day 29

  4. Geometric Mean Increase (GMI) of Antigen 1 Titer

    Time frame: Day 1 to Day 29

  5. GMT Of Antigen 2 Titer

    Time frame: At Day 29

  6. Percentage of Participants with Antigen 2 SCR

    Time frame: Day 1 to Day 29

  7. GMI of Antigen 2 Titer

    Time frame: Day 1 to Day 29

  8. GMT ratio of serum neutralization titers against pseudovirus bearing spike from SARS-CoV-2 vaccine matched variant(s)

    Time frame: At Day 29

  9. Percentage of participants with seroresponse of neutralization titers against pseudovirus bearing spike from SARS-CoV-2 vaccine matched variant(s)

    Time frame: Day 1 to Day 29

  10. GMI of neutralization titers against pseudovirus bearing spike from SARS-CoV-2 vaccine matched variant(s)

    Time frame: Day 1 to Day 29

Study contacts

Contact information is provided by the study sponsor or research team.

EU GSK Clinical Trials Call Center

CONTACT

[email protected]

+44 (0) 20 89904466

US GSK Clinical Trials Call Center

CONTACT

[email protected]

877-379-3718

Sponsors and collaborators

Lead sponsor

GlaxoSmithKline

Industry

Registry information

Official study title

A Phase 1, Observer-Blind, Randomized, Controlled Study to Evaluate the Safety and Immunogenicity of an Investigational mRNA Seasonal Flu/COVID-19 Combination Vaccine in Adults

Important dates

Study start
2026
Primary completion
2026
Study completion
2027
First posted
Mar 11, 2026
Registry last updated
Jun 30, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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