Respiratory Syncytial Virus InfectionsPhase 3NCT06374394
A Study on the Immune Response and Safety of a Vaccine Against Respiratory Syncytial Virus (RSV) When Given Alone and Together With a COVID-19 mRNA Vaccine in Adults Aged 50 Years and Above
A Phase 3 study testing RSVPreF3 OA investigational vaccine and COVID-19 mRNA vaccine in people with Respiratory Syncytial Virus Infections, run by GlaxoSmithKline at 24 sites in 4 countries.
Trial summary
This study is assessing the immunogenicity, safety and reactogenicity of the RSVPreF3 OA investigational vaccine when it is co-administered with a COVID-19 messenger ribonucleic acid (mRNA) vaccine (Omicron XBB.1.5), compared to administration of the vaccines separately in adults aged 50 years and above. Read more about this study
- Who is it for?
- Ages 50 years and olderHealthy volunteers can take part
- Conditions the study is for
- Respiratory Syncytial Virus Infections
- What is being tested?
- RSVPreF3 OA investigational vaccine and COVID-19 mRNA vaccine
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 841 participants
- Where
- 24 sitesin 4 countries
- Study dates
- 29 Apr 2024to 31 Mar 2025
- Phase
- Phase 3
- 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 50 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participants, who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the diary cards, return for follow-up visits).
- Note: In case of physical incapacity that would preclude the self-completion of the diary cards, either site staff can assist the participant (for activities performed during site visits) or the participant may assign a caregiver to assist him/her with this activity (for activities performed at home). However, at no time will the site staff or caregiver evaluate the participant's health status while answering diaries or make decisions on behalf of the participant.
- Written or witnessed informed consent obtained from the participant (participant must be able to understand the informed consent) prior to performance of any study-specific procedure.
- A male/female of ≥50 Years of age (YOA) at the time of the first study intervention administration.
- Participants who are medically stable in the opinion of the investigator at the time of first vaccination. Participants with chronic stable medical conditions with or without specific treatment, such as diabetes, hypertension or cardiac disease, are allowed to participate in this study if considered by the investigator as medically stable.
- 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.
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- Participants living in the general community or in an assisted-living facility that provides minimal assistance, such that the participant is primarily responsible for self-care and activities of daily living.
- Participants who have received previously a SARS-CoV-2 vaccine, being administered at least 3 months prior to study vaccination.
- Female participants of non-childbearing potential may be enrolled in the study. Non childbearing potential is defined as hysterectomy, bilateral oophorectomy, bilateral salpingectomy, and post-menopause.
- Female participants of childbearing potential may be enrolled in the study if the participant.
- has practiced adequate contraception from 1 month prior to study intervention administration and agreed to continue adequate contraception for at least 1 month after the last vaccination.
- has a negative pregnancy test on the day of and prior to study intervention administration.
Who cannot join
- Medical Conditions
- History of any reaction or hypersensitivity likely to be exacerbated by any component of the study interventions, including a known history of severe allergic reaction (e.g., anaphylaxis).
- Any confirmed or suspected immunosuppressive or immunodeficient condition, resulting from disease (e.g., current malignancy, human immunodeficiency virus) or immunosuppressive/cytotoxic therapy (e.g., medication used during cancer chemotherapy, organ transplantation, or to treat autoimmune disorders), based on medical history and physical examination (no laboratory testing required).
- Any history of myocarditis or pericarditis.
- Recurrent history or uncontrolled neurological disorders or seizures. Participants with medically-controlled active or chronic neurological diseases can be enrolled in the study as per investigator assessment, provided that their condition will allow them to comply with the requirements of the protocol (e.g. completion of diary cards, attend regular phone calls/study site visits).
- Serious or unstable chronic illness.
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- Any history of dementia or any medical condition that moderately or severely impairs cognition.
- Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study (e.g., life-threatening disease likely to limit survival up to study end).
- Any medical condition that in the judgment of the investigator would make intramuscular injection unsafe.
- Any SAE attributed to a previous dose of the SARS-CoV-2 mRNA vaccine.
- Any other clinical condition that, in the opinion of the investigator, might pose additional risk to the participant due to participation in the study.
- Recent SARS-CoV-2 infection within 3 months prior to the COVID-19 vaccine dose administration. Timelines to be determined from symptoms onset or positive COVID-19 test (if infection was asymptomatic).
- Prior/Concomitant Therapy Use of any investigational or non-registered product (drug, vaccine or invasive medical device) other than the study interventions during the period beginning 30 days before the first dose of study interventions and ending 30 days after the last vaccine administration, or their planned use during the study period.
- Planned administration of a vaccine in the period starting 30 days before the first dose and ending 30 days after the last dose of study intervention(s) administration*, with the exception of inactivated and subunit influenza vaccines which can be administered up to 14 days before or from 14 days after the study vaccination.
- If emergency mass vaccination for an unforeseen public health threat (e.g., a pandemic) is recommended and/or organized by public health authorities outside the routine immunization program, the time period described above can be reduced if necessary for that vaccine, provided it is used according to the local governmental recommendations and Sponsor is notified.
- Chronic administration of immune-modifying drugs (defined as more than 14 consecutive days in total) and/or planned use of long-acting immune-modifying treatments at any time up to the last blood sampling visit.
- Up to 3 months prior to the study intervention administration:
- For corticosteroids, this will mean prednisone equivalent ≥ 20 mg/day. Inhaled and topical steroids are allowed.
- Administration of immunoglobulins and/or any blood products or plasma derivatives.
- Up to 6 months prior to study intervention administration: long-acting immune modifying drugs including among others immunotherapy (e.g., TNF-inhibitors), monoclonal antibodies and antitumoral medication.
- Administration of any SARS-CoV-2 vaccine during the 3 months preceding the study COVID-19 mRNA vaccine administration.
- Previous vaccination with licensed or investigational RSV vaccine. Prior/Concurrent Clinical Study Experience
- Concurrently participating in another clinical study, at any time during the study period, in which the participant has been or will be exposed to an investigational or a non-investigational intervention (drug/invasive medical device).
- Other Exclusion Criteria
- Pregnant or lactating female participant.
- Female participant planning to become pregnant or planning to discontinue contraceptive precautions.
- 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.
- Participation of any study personnel or their immediate dependents, family, or household members.
- Planned move during the study conduct that prohibits participation until study end.
- Bedridden participants.
Trial locations and contacts
24 sites in 4 countries.
24 sites in 4 countries
United States8 sites
GSK Investigational Site
Coral Gables, Florida, 33134
GSK Investigational Site
Evansville, Indiana, 47714
GSK Investigational Site
Newport News, Virginia, 23606
GSK Investigational Site
North Charleston, South Carolina, 29405
GSK Investigational Site
Omaha, Nebraska, 68134
GSK Investigational Site
Rochester, New York, 14609
GSK Investigational Site
Savannah, Georgia, 31406
GSK Investigational Site
Winston-Salem, North Carolina, 27103
Spain7 sites
GSK Investigational Site
A Coruña, 15006
GSK Investigational Site
Barcelona, 08023
GSK Investigational Site
Barcelona, 08907
GSK Investigational Site
Boadilla Del Monte Madrid, 28660
GSK Investigational Site
Madrid, 28040
GSK Investigational Site
Madrid, 28041
GSK Investigational Site
Madrid, 28222
Belgium5 sites
GSK Investigational Site
Antwerp, 2000
GSK Investigational Site
Edegem, 2650
GSK Investigational Site
Ghent, 9000
GSK Investigational Site
Kluisbergen, 9690
GSK Investigational Site
Mechelen, 2800
Netherlands4 sites
GSK Investigational Site
Breda, 4818 CK
GSK Investigational Site
Enschede, 7512 KZ
GSK Investigational Site
Utrecht, 3584 BA
GSK Investigational Site
Zutphen, 7207 AE
About this study
Official title: A Phase 3, Open-label, Randomized, Controlled Study to Evaluate the Immune Response, Safety and Reactogenicity of RSVPreF3 OA Investigational Vaccine When Co-Administered With a COVID-19 mRNA Vaccine (Omicron XBB.1.5) in Adults Aged 50 Years and Above
This study is assessing the immunogenicity, safety and reactogenicity of the RSVPreF3 OA investigational vaccine when it is co-administered with a COVID-19 messenger ribonucleic acid (mRNA) vaccine (Omicron XBB.1.5), compared to administration of the vaccines separately in adults aged 50 years and above.
- Conditions
- Respiratory Syncytial Virus Infections
- Being tested
- RSVPreF3 OA investigational vaccine, COVID-19 mRNA vaccine
- Keywords
- RSV, Respiratory Syncytial Virus, COVID-19 mRNA vaccine, Immunogenicity, Safety, Reactogenicity, Older Adults
- Medical subject headings
- Respiratory Syncytial Virus Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RSVPreF3 OA investigational vaccineBiological
1 dose of RSVPreF3 OA investigational vaccine is administered intramuscularly on Day 1 to participants in the Co-ad Group and on Day 31 to participants in the Control Group.
COVID-19 mRNA vaccineBiological
1 dose of COVID-19 mRNA vaccine is administered intramuscularly on Day 1 to participants in the Co-ad and Control Groups.
| Study group | Role | What they receive |
|---|---|---|
| Co-Ad Group | Experimental | Participants received a single dose of RSVPreF3 OA vaccine and a single dose of COVID-19 mRNA vaccine at Day 1, in different arms. Receives: Biological: RSVPreF3 OA investigational vaccine; Biological: COVID-19 mRNA vaccine |
| Control Group | Active comparator | Participants received a single dose of COVID-19 mRNA vaccine at Day 1, followed by a single dose of RSVPreF3 OA vaccine at Day 31. Receives: Biological: RSVPreF3 OA investigational vaccine; Biological: COVID-19 mRNA vaccine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Adjusted Geometric Mean Titers (GMT) of Respiratory Syncytial Virus-A (RSV-A) Neutralizing Titers at 1 Month After the RSVPreF3 OA Vaccination
RSV-A neutralizing titers were provided as group GMTs and expressed as estimated dilution 60 (ED60) titers. Adjusted GMTs are derived using an ANCOVA model on log10-transformed titers for the neutralization assay. The final ANCOVA model adjusted for baseline differences (in the pre-dose titers) includes treatment group and age category (age at vaccination: 50-59, 60-69 or ≥70 years) as fixed effects, and the pre-dose log10-transformed titers as a covariate.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
Adjusted GMTs of RSV-B Neutralizing Titers at 1 Month After the RSVPreF3 OA Vaccination
RSV-B neutralizing titers were provided as group GMTs and expressed as estimated dilution 60 (ED60) titers. Adjusted GMTs are derived using an ANCOVA model on log10-transformed titers for the neutralization assay. The final ANCOVA model adjusted for baseline differences (in the pre-dose titers) includes treatment group and age category (age at vaccination: 50-59, 60-69 or ≥70 years) as fixed effects, and the pre-dose log10-transformed titers as a covariate.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
Adjusted GMTs of SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers at 1 Month After the COVID-19 mRNA Vaccination
SARS-CoV-2 Omicron XBB.1.5 neutralizing titers against the pseudovirus bearing S protein were provided as group GMTs and expressed as titers. The neutralizing titer was calculated as the reciprocal serum dilution corresponding to the 50% signal reduction (NT50). Adjusted GMTs are derived using an ANCOVA model on log10-transformed titers for the neutralization assay. The final ANCOVA model adjusted for baseline differences (in the pre-dose titers) includes treatment group and age category (age at vaccination: 50-59, 60-69 or ≥70 years) as fixed effects, and the pre-dose log10-transformed titers as a covariate.
Measured: At 1 month post-COVID-19 mRNA vaccine dose administration (at Day 31 for both groups)
Secondary outcomes (16)
RSV-A Neutralizing Titers Expressed as GMT at 1 Month After RSVPreF3 OA Vaccination
Neutralizing titers for RSV-A were measured with neutralizing assay and the results were expressed as GMT. GMT is a descriptive statistic calculated directly from the observed titer values at the 1-month post-vaccination timepoint for all participants in the analysis set, without any statistical modelling or adjustment for covariates.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
Mean Geometric Increase (MGI) of RSV-A Neutralizing Titers at 1 Month After RSVPreF3 OA Vaccination
The MGI was defined as the geometric mean of the within participant ratios of the post-vaccination titer over the pre-vaccination titer.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
RSV-A Neutralizing Titers Expressed as Seroresponse Rate (SRR) at 1 Month After RSVPreF3 OA Vaccination
The SRR was defined as the percentage of participants having a fold increase in neutralizing titers (1 month post-study intervention administration over pre-study intervention administration) greater than or equal to (>=) 4.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
Percentage of Participants Having RSV-A Neutralizing Titers Greater or Equal to the Assay Cut-off Value at Pre-vaccination and at 1 Month After RSVPreF3 OA Vaccination
Percentage of participants with RSV-A neutralizing titers >= to the assay cut-off value (i.e. lower limit of quantification [LLOQ]) are presented.
Measured: At pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group) and at 1 month post-RSVPreF3 OA vaccine dose administration (Day 31 for Co-Ad Group and Day 61 for Control Group)
RSV-B Neutralizing Titers Expressed as GMT at 1 Month After RSVPreF3 OA Vaccination
Neutralizing titers for RSV-B were measured with neutralizing assay and the results were expressed as GMT. GMT is a descriptive statistic calculated directly from the observed titer values at the 1-month post-vaccination timepoint for all participants in the analysis set, without any statistical modelling or adjustment for covariates.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
MGI of RSV-B Neutralizing Titers at 1 Month After RSVPreF3 OA Vaccination
The MGI was defined as the geometric mean of the within participant ratios of the post-vaccination titer over the pre-vaccination titer.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
RSV-B Neutralizing Titers Expressed as SRR at 1 Month After RSVPreF3 OA Vaccination
The SRR was defined as the percentage of participants having a fold increase in neutralizing titers (1 month post-study intervention administration over pre-study intervention administration) >= 4.
Measured: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
Percentage of Participants Having RSV-B Neutralizing Titers Greater or Equal to Assay Cut-off Value at Pre-vaccination and at 1 Month After RSVPreF3 OA Vaccination
Percentage of participants with RSV-B neutralizing titers >= to the assay cut-off value (i.e. LLOQ) are presented.
Measured: At pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group) and at 1 month post-RSVPreF3 OA vaccine dose administration (Day 31 for Co-Ad Group and Day 61 for Control Group)
SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers Expressed as GMT at 1 Month After COVID-19 mRNA Vaccination
The SARS-CoV-2 Omicron XBB.1.5 neutralizing titers against the pseudovirus bearing S protein were measured with neutralizing assay and the results were expressed as GMT. GMT is a descriptive statistic calculated directly from the observed titer values at the 1-month post-vaccination timepoint for all participants in the analysis set, without any statistical modelling or adjustment for covariates.
Measured: At 1 month post-COVID-19 mRNA vaccine dose administration (Day 31 for both groups)
MGI of SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers at 1 Month After COVID-19 mRNA Vaccination
The MGI was defined as the geometric mean of the within participant ratios of the post-vaccination titer over the pre-vaccination titer.
Measured: At 1 month post-COVID-19 mRNA vaccine dose administration (Day 31 for both groups) compared to pre-vaccination (at Day 1 for both groups)
Percentage of Participants Having SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers Greater Than or Equal to Assay Cut-off Value at Pre-vaccination and at 1 Month After COVID-19 mRNA Vaccination
Percentage of participants with SARS-CoV-2 Omicron XBB.1.5 neutralizing titers >= to the assay cut-off value (i.e. LLOQ) are presented.
Measured: At pre-vaccination (Day 1 for both groups) and at 1 month post-COVID-19 mRNA vaccine dose administration (Day 31 for both groups)
Number of Participants Reporting Each Solicited Administration Site Event, for Each Type of Vaccine Administered
The solicited administration site events after vaccination included pain, erythema/redness, and swelling. Any = occurrence of the events regardless of the intensity grade.
Measured: Within 4 days (the day of administration and 3 subsequent days) after each type of vaccine (RSVPreF3 OA vaccine administered at Day 1 for Co-Ad Group and at Day 31 for Control Group, COVID-19 mRNA vaccine administered at Day 1 for both groups)
Number of Participants Reporting Each Solicited Systemic Event, for Each Day of Dose Administered
The solicited systemic events after vaccination included arthralgia, fatigue, fever (pyrexia), headache and myalgia. Fever was defined as body temperature equal or greater than 38 degrees Celsius (°C). Any = occurrence of the events regardless of the intensity grade.
Measured: Within 4 days (the day of dose administered and 3 subsequent days) after each dose (administered at Day 1 for Co-Ad Group and at Days 1 and 31 for Control Group)
Number of Participants Reporting Unsolicited Adverse Events (AEs), for Each Day of Dose Administered
An AE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study vaccine, which does not necessarily have a causal relationship with study vaccine. An unsolicited AE was 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. Unsolicited AEs must had been communicated by participant/participant's caregiver(s) who had signed the informed consent. Unsolicited AEs included both serious and non-serious AEs. Any = occurrence of the events regardless of the intensity grade or relation to study dose administration.
Measured: Within 30 days (the day of vaccination and 29 subsequent days) after each dose (dose administered at Day 1 for Co-Ad Group and at Days 1 and 31 for Control Group)
Number of Participants Reporting Any Serious Adverse Events (SAEs)
An SAE was defined as any untoward medical occurrence that, at any dose, resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect, or was an important medical event. Any = occurrence of the events regardless of the intensity grade or relation to study dose administration.
Measured: Throughout the study period (from Day 1 up to 6 months after the last dose administration [last dose given at Day 1 for Co-Ad Group and Day 31 for Control Group])
Number of Participants Reporting Any Potential Immune-mediated Diseases (pIMDs)
The pIMD was defined as a subset of adverse events of special interest that included autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology. Any = occurrence of the events regardless of the intensity grade or relation to study dose administration.
Measured: Throughout the study period (from Day 1 up to 6 months after the last dose administration [last dose given at Day 1 for Co-Ad Group and Day 31 for Control Group])
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Apr 2024
- Study start29 Apr 2024
- Primary completion1 Nov 2024
- Study completion31 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Respiratory Syncytial Virus InfectionsStudies of the same condition, open and under way.
- More trials run by GlaxoSmithKlineThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 3
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 841 participants (actual)
Sponsor and investigators
- Lead sponsor
- GlaxoSmithKline
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06374394
- Sponsor's protocol ID
- 217848
- Other IDs
- 2023-510196-59-00, 2023
- Status last verified
- Dec 2025
- First submitted
- 16 Apr 2024
- Last updated
- 26 Dec 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: GSK will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/About\_GSK\_Patient\_Level\_Data\_Sharing\_Final\_13July2023.pdf.
Study at a glance
From the registry record, last updated by the sponsor on 26 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 3, Open-label, Randomized, Controlled Study to Evaluate the Immune Response, Safety and Reactogenicity of RSVPreF3 OA Investigational Vaccine When Co-Administered With a COVID-19 mRNA Vaccine (Omicron XBB.1.5) in Adults Aged 50 Years and Above
- ClinicalTrials.gov ID
- NCT06374394
- Acronym / sponsor ID
- 217848
- Conditions
- Respiratory Syncytial Virus Infections
- Keywords
- RSV, Respiratory Syncytial Virus, COVID-19 mRNA vaccine, Immunogenicity, Safety, Reactogenicity, Older Adults
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 841 participants (actual)
- Lead sponsor
- GlaxoSmithKlineIndustry (pharma, biotech, devices)
- Study start
- 29 Apr 2024 (actual)
- Primary completion
- 1 Nov 2024 (actual)
- Study completion
- 31 Mar 2025 (actual)
- First posted
- 18 Apr 2024 (actual)
- Results
- Posted 26 Dec 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is assessing the immunogenicity, safety and reactogenicity of the RSVPreF3 OA investigational vaccine when it is co-administered with a COVID-19 messenger ribonucleic acid (mRNA) vaccine (Omicron XBB.1.5), compared to administration of the vaccines separately in adults aged 50 years and above.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Co-Ad Group | Experimental | Biological: RSVPreF3 OA investigational vaccine, Biological: COVID-19 mRNA vaccineParticipants received a single dose of RSVPreF3 OA vaccine and a single dose of COVID-19 mRNA vaccine at Day 1, in different arms. |
| Control Group | Active comparator | Biological: RSVPreF3 OA investigational vaccine, Biological: COVID-19 mRNA vaccineParticipants received a single dose of COVID-19 mRNA vaccine at Day 1, followed by a single dose of RSVPreF3 OA vaccine at Day 31. |
Who may qualify
- Ages
- 50 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (12 listed)
- Participants, who, in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the diary cards, return for follow-up visits).
- Note: In case of physical incapacity that would preclude the self-completion of the diary cards, either site staff can assist the participant (for activities performed during site visits) or the participant may assign a caregiver to assist him/her with this activity (for activities performed at home). However, at no time will the site staff or caregiver evaluate the participant's health status while answering diaries or make decisions on behalf of the participant.
- Written or witnessed informed consent obtained from the participant (participant must be able to understand the informed consent) prior to performance of any study-specific procedure.
- A male/female of ≥50 Years of age (YOA) at the time of the first study intervention administration.
- Participants who are medically stable in the opinion of the investigator at the time of first vaccination. Participants with chronic stable medical conditions with or without specific treatment, such as diabetes, hypertension or cardiac disease, are allowed to participate in this study if considered by the investigator as medically stable.
Key exclusion criteria (30 listed)
- Medical Conditions
- History of any reaction or hypersensitivity likely to be exacerbated by any component of the study interventions, including a known history of severe allergic reaction (e.g., anaphylaxis).
- Any confirmed or suspected immunosuppressive or immunodeficient condition, resulting from disease (e.g., current malignancy, human immunodeficiency virus) or immunosuppressive/cytotoxic therapy (e.g., medication used during cancer chemotherapy, organ transplantation, or to treat autoimmune disorders), based on medical history and physical examination (no laboratory testing required).
- Any history of myocarditis or pericarditis.
- Recurrent history or uncontrolled neurological disorders or seizures. Participants with medically-controlled active or chronic neurological diseases can be enrolled in the study as per investigator assessment, provided that their condition will allow them to comply with the requirements of the protocol (e.g. completion of diary cards, attend regular phone calls/study site visits).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| RSVPreF3 OA investigational vaccine1 dose of RSVPreF3 OA investigational vaccine is administered intramuscularly on Day 1 to participants in the Co-ad Group and on Day 31 to participants in the Control Group. | Biological | Co-Ad Group, Control Group |
| COVID-19 mRNA vaccine1 dose of COVID-19 mRNA vaccine is administered intramuscularly on Day 1 to participants in the Co-ad and Control Groups. | Biological | Co-Ad Group, Control Group |
Primary outcome
Adjusted Geometric Mean Titers (GMT) of Respiratory Syncytial Virus-A (RSV-A) Neutralizing Titers at 1 Month After the RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
RSV-A neutralizing titers were provided as group GMTs and expressed as estimated dilution 60 (ED60) titers. Adjusted GMTs are derived using an ANCOVA model on log10-transformed titers for the neutralization assay. The final ANCOVA model adjusted for baseline differences (in the pre-dose titers) includes treatment group and age category (age at vaccination: 50-59, 60-69 or ≥70 years) as fixed effects, and the pre-dose log10-transformed titers as a covariate.
Adjusted GMTs of RSV-B Neutralizing Titers at 1 Month After the RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
RSV-B neutralizing titers were provided as group GMTs and expressed as estimated dilution 60 (ED60) titers. Adjusted GMTs are derived using an ANCOVA model on log10-transformed titers for the neutralization assay. The final ANCOVA model adjusted for baseline differences (in the pre-dose titers) includes treatment group and age category (age at vaccination: 50-59, 60-69 or ≥70 years) as fixed effects, and the pre-dose log10-transformed titers as a covariate.
Adjusted GMTs of SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers at 1 Month After the COVID-19 mRNA Vaccination
Time frame: At 1 month post-COVID-19 mRNA vaccine dose administration (at Day 31 for both groups)
SARS-CoV-2 Omicron XBB.1.5 neutralizing titers against the pseudovirus bearing S protein were provided as group GMTs and expressed as titers. The neutralizing titer was calculated as the reciprocal serum dilution corresponding to the 50% signal reduction (NT50). Adjusted GMTs are derived using an ANCOVA model on log10-transformed titers for the neutralization assay. The final ANCOVA model adjusted for baseline differences (in the pre-dose titers) includes treatment group and age category (age at vaccination: 50-59, 60-69 or ≥70 years) as fixed effects, and the pre-dose log10-transformed titers as a covariate.
16 secondary outcomes
RSV-A Neutralizing Titers Expressed as GMT at 1 Month After RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
Mean Geometric Increase (MGI) of RSV-A Neutralizing Titers at 1 Month After RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
RSV-A Neutralizing Titers Expressed as Seroresponse Rate (SRR) at 1 Month After RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
Percentage of Participants Having RSV-A Neutralizing Titers Greater or Equal to the Assay Cut-off Value at Pre-vaccination and at 1 Month After RSVPreF3 OA Vaccination
Time frame: At pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group) and at 1 month post-RSVPreF3 OA vaccine dose administration (Day 31 for Co-Ad Group and Day 61 for Control Group)
RSV-B Neutralizing Titers Expressed as GMT at 1 Month After RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)
MGI of RSV-B Neutralizing Titers at 1 Month After RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
RSV-B Neutralizing Titers Expressed as SRR at 1 Month After RSVPreF3 OA Vaccination
Time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group) compared to pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group)
Percentage of Participants Having RSV-B Neutralizing Titers Greater or Equal to Assay Cut-off Value at Pre-vaccination and at 1 Month After RSVPreF3 OA Vaccination
Time frame: At pre-vaccination (Day 1 for Co-Ad Group and Day 31 for Control Group) and at 1 month post-RSVPreF3 OA vaccine dose administration (Day 31 for Co-Ad Group and Day 61 for Control Group)
SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers Expressed as GMT at 1 Month After COVID-19 mRNA Vaccination
Time frame: At 1 month post-COVID-19 mRNA vaccine dose administration (Day 31 for both groups)
MGI of SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers at 1 Month After COVID-19 mRNA Vaccination
Time frame: At 1 month post-COVID-19 mRNA vaccine dose administration (Day 31 for both groups) compared to pre-vaccination (at Day 1 for both groups)
Percentage of Participants Having SARS-CoV-2 Omicron XBB.1.5 Neutralizing Titers Greater Than or Equal to Assay Cut-off Value at Pre-vaccination and at 1 Month After COVID-19 mRNA Vaccination
Time frame: At pre-vaccination (Day 1 for both groups) and at 1 month post-COVID-19 mRNA vaccine dose administration (Day 31 for both groups)
Number of Participants Reporting Each Solicited Administration Site Event, for Each Type of Vaccine Administered
Time frame: Within 4 days (the day of administration and 3 subsequent days) after each type of vaccine (RSVPreF3 OA vaccine administered at Day 1 for Co-Ad Group and at Day 31 for Control Group, COVID-19 mRNA vaccine administered at Day 1 for both groups)
Number of Participants Reporting Each Solicited Systemic Event, for Each Day of Dose Administered
Time frame: Within 4 days (the day of dose administered and 3 subsequent days) after each dose (administered at Day 1 for Co-Ad Group and at Days 1 and 31 for Control Group)
Number of Participants Reporting Unsolicited Adverse Events (AEs), for Each Day of Dose Administered
Time frame: Within 30 days (the day of vaccination and 29 subsequent days) after each dose (dose administered at Day 1 for Co-Ad Group and at Days 1 and 31 for Control Group)
Number of Participants Reporting Any Serious Adverse Events (SAEs)
Time frame: Throughout the study period (from Day 1 up to 6 months after the last dose administration [last dose given at Day 1 for Co-Ad Group and Day 31 for Control Group])
Number of Participants Reporting Any Potential Immune-mediated Diseases (pIMDs)
Time frame: Throughout the study period (from Day 1 up to 6 months after the last dose administration [last dose given at Day 1 for Co-Ad Group and Day 31 for Control Group])
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Dec 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. GSK will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer to https://www.gsk-studyregister.com/About_GSK_Patient_Level_Data_Sharing_Final_13July2023.pdf.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
24 sites in 4 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing RSVPreF3 OA investigational vaccine and COVID-19 mRNA vaccine in people with Respiratory Syncytial Virus Infections, run by GlaxoSmithKline at 24 sites in 4 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 12 inclusion and 30 exclusion criteria. 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 26 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 24 sites in United States, Spain, Belgium, Netherlands. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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 26 Dec 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?
Adjusted Geometric Mean Titers (GMT) of Respiratory Syncytial Virus-A (RSV-A) Neutralizing Titers at 1 Month After the RSVPreF3 OA Vaccination (time frame: At 1 month post-RSVPreF3 OA vaccine dose administration (at Day 31 for Co-Ad Group and Day 61 for Control Group)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 26 Dec 2025.