Last updated: 03/23/2026 11:10:12
A study on the safety and immune response of investigational mRNA Seasonal Flu/COVID-19 combination vaccine in adults
GSK study ID
300768
Clinicaltrials.gov ID
EudraCT ID
Not applicable
EU CT Number
Not applicable
Trial status
Recruiting
Recruiting
Trial overview
Official 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
Trial description: 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.
Primary purpose:
Prevention
Trial design:
Sequential
Masking:
Triple (Participant, Investigator, Outcomes Assessor)
Allocation:
Randomized
Primary outcomes:
Number of Participants with an Increase in Toxicity Grade of Laboratory Value Abnormalities Following Administration of the Study Intervention
Timeframe: Day 1 to Day 3
Number of Participants with an Increase in Toxicity Grade of Laboratory Value Abnormalities following Administration of Study Intervention
Timeframe: Day 1 to Day 8
Number of Participants with an Increase in Toxicity Grade of Laboratory Value Abnormalities following Administration of Study Intervention
Timeframe: Day 1 to Day 29
Number of Participants with Solicited Administration Site Adverse Events (AEs)
Timeframe: Day 1 to Day 7
Number of Participants with Solicited Systemic AEs
Timeframe: Day 1 to Day 7
Number of Participants with Unsolicited AEs
Timeframe: Day 1 to Day 28
Number of Participants with Serious Adverse Events (SAEs)
Timeframe: Day 1 to Day 181
Number of Participants with Adverse Events of Special Interest (AESIs)
Timeframe: Day 1 to Day 181
Number of Participants with Medically Attended Adverse Events (MAAEs)
Timeframe: Day 1 to Day 181
Secondary outcomes:
Geometric Mean Titer (GMT) Of Antigen 1 Titer
Timeframe: At Day 29
Percentage of Participants with Antigen 1 Seroconversion Rate (SCR)
Timeframe: Day 1 to Day 29
Percentage of Participants with Antigen 1 Seroprotection Rate (SPR)
Timeframe: At Day 1 and Day 29
Geometric Mean Increase (GMI) of Antigen 1 Titer
Timeframe: Day 1 to Day 29
GMT Of Antigen 2 Titer
Timeframe: At Day 29
Percentage of Participants with Antigen 2 SCR
Timeframe: Day 1 to Day 29
GMI of Antigen 2 Titer
Timeframe: Day 1 to Day 29
GMT ratio of serum neutralization titers against pseudovirus bearing spike from SARS-CoV-2 vaccine matched variant(s)
Timeframe: At Day 29
Percentage of participants with seroresponse of neutralization titers against pseudovirus bearing spike from SARS-CoV-2 vaccine matched variant(s)
Timeframe: Day 1 to Day 29
GMI of neutralization titers against pseudovirus bearing spike from SARS-CoV-2 vaccine matched variant(s)
Timeframe: Day 1 to Day 29
Interventions:
Biological/vaccine: Investigational mRNA Seasonal Flu/COVID-19 Combination (Flu/COVm) Vaccine
Biological/vaccine: Licensed Seasonal Influenza Vaccine
Biological/vaccine: Licensed COVID-19 Vaccine
Enrollment:
225
Observational study model:
Not applicable
Primary completion date:
2026-03-12
Time perspective:
Not applicable
Clinical publications:
Not applicable
Medical condition
Influenza, Human+COVID-19
Product
Not applicable
Collaborators
Not applicable
Study date(s)
March 2026 to June 2027
Type
Interventional
Phase
1
Participation criteria
Sex
Female & Male
Age
65 - 85 Years
Accepts healthy volunteers
No
- 1. 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.
- 2. Informed consent obtained from the participant prior to performance of any study-specific procedure.
- 1. Any clinically significant laboratory abnormality.
- 2. 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.
Inclusion and exclusion criteria
Inclusion criteria:
- 1. 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. 2. Informed consent obtained from the participant prior to performance of any study-specific procedure. 3. A male or female 65 to 85 years of age (YoA) (inclusive) at the time of screening. 4. Healthy participants or medically stable patients as established by medical history and clinical examination. 5. Other protocol-defined inclusion criteria may apply.
Exclusion criteria:
- 1. Any clinically significant laboratory abnormality. 2. 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. 3. History of Guillain-Barré syndrome (GBS) within 6 weeks of receiving any vaccine. 4. 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. 5. Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required). 6. 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. 7. History of any reaction or hypersensitivity likely to be exacerbated by any component of the study intervention(s). 8. Acute or unstable chronic conditions, clinically significant pulmonary, cardiovascular, or renal functional abnormality, as determined by physical examination and/or laboratory screening tests. 9. History of hypersensitivity or allergic reaction to any previous influenza or COVID-19 vaccine. 10. History of hypersensitivity or allergic reaction to any previous mRNA vaccine. 11. 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. 12. 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. 13. 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. 14. 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. 15. Other protocol-defined exclusion criteria may apply.
Trial location(s)
Study documents
No study documents available.
Results overview
Study Results yet to be posted
Recruitment status
Recruiting
Actual primary completion date
Not applicable
Actual study completion date
Not applicable
Plain language summaries
Plain language summaries of clinical trial results for Phase 2-4 clinical trials that were initiated on or after January 2022 will be posted by GSK within one year following study completion.
Additional information about the trial
Additional information
Not applicable
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