Respiratory Syncytial VirusPhase 3NCT06593587
A Study to Assess the Safety, Tolerability, and Immunogenicity of RSVpreF in Older Adults in Korea
A Phase 3 study testing RSVpreF Vaccine in people with Respiratory Syncytial Virus, run by Pfizer at 16 sites in South Korea.
Trial summary
The goal of this clinical trial is to quantify the immune response in older Korean adults after a RSVpreF vaccination. It will also learn about the safety and tolerability of RSVpreF vaccination. Read more about this study
- Who is it for?
- Ages 60 years and olderHealthy volunteers can take part
- Conditions the study is for
- Respiratory Syncytial Virus
- What is being tested?
- RSVpreF Vaccine
- Type of treatment
- Vaccines
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 378 participants
- Where
- 16 sitesSouth Korea
- Study dates
- 7 Oct 2024to 3 Feb 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 60 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participants 60 years of age or older at Visit 1
- Male participants able to father children must agree to use a highly effective method of contraception from the time of informed consent through at least 28 days after study intervention administration
- Female participants must not be of childbearing potential
- Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study.
- Healthy participants with preexisting 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.
- Participants who are willing and able to comply with all scheduled visits, investigational plan, laboratory tests, frequent symptom assessment by mobile device application (e-diary), and other study procedures.
- Participants who are ambulatory and live in the community, or in assisted-living or long-term care residential facilities that provide minimal assistance, such that the participant is primarily responsible for self-care and activities of daily living (ADL).
- Capable of giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent document (ICD) and the protocol.
Who cannot join
- A confirmed diagnosis of RSV infection ≤180 days before study intervention administration.
- Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular (IM) injection.
- Prior history of any subtype of Guillain-Barré syndrome (GBS) of any etiology.
- History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s) or any related vaccine.
- Serious chronic disorder, including metastatic malignancy, end-stage renal disease with or without dialysis, clinically unstable cardiac disease, or any other disorder that, in the investigator's opinion, excludes the participant from participating in the study.
- Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
Show all 16Show fewer
- Any medical or psychiatric condition, including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality, that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
- Individuals who receive chronic systemic treatment with immunosuppressive therapy (other than systemic corticosteroids meeting the criteria noted below), including cytotoxic agents, immunosuppressive monoclonal antibodies, or radiotherapy, eg, for cancer or an autoimmune disease, from 60 days before study intervention administration or planned receipt throughout the study.
- Receipt of systemic corticosteroids (≥20 mg/day of prednisone or equivalent) for
- ≥14 days from 28 days before study intervention.
- Inhaled/nebulized, intra articular, intrabursal, or topical (skin or eyes) corticosteroids are permitted.
- Receipt of blood/plasma products or immunoglobulin within 60 days before study intervention administration.
- Previous vaccination with any licensed or investigational RSV vaccine, or planned receipt throughout the study.
- Previous administration with an investigational product (drug or vaccine) within 6 months prior to study intervention administration. Participation in other studies involving an investigational product (drug or vaccine) at any time during participation in this study.
- Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members.
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Trial locations and contacts
16 sites in 1 country.
16 sites in 1 country
South Korea16 sites
Korea University Ansan Hospital
Ansan-si, Kyǒnggi-do, 15355
Soon Chun Hyang University Bucheon Hospital
Bucheon-si, Kyǒnggi-do, 14584
Dong-A University Hospital
Busan, Pusan-kwangyǒkshi, 49201
Kyungpook National University Hospital
Daegu, Taegu-kwangyǒkshi, 41944
Chonnam National University Hospital
Gwangju, Kwangju-kwangyǒkshi, 61469
Inha University Hospital
Incheon, Incheon-gwangyeoksi [incheon], 22332
Jeonbuk National University Hospital
Jeonju, Jeonrabugdo, 54907
Severance Hospital, Yonsei University Health System
Seoul, Seoul-teukbyeolsi [seoul], 03722
Hallym University Kangdong Sacred Heart Hospital
Seoul, Seoul-teukbyeolsi [seoul], 05355
Samsung Medical Center
Seoul, Seoul-teukbyeolsi [seoul], 06351
The Catholic Univ. of Korea Seoul St. Mary's Hospital
Seoul, Seoul-teukbyeolsi [seoul], 06591
Hallym University Kangnam Sacred Heart Hospital
Seoul, Seoul-teukbyeolsi [seoul], 07441
Ewha Womans University Mokdong Hospital
Seoul, Seoul-teukbyeolsi [seoul], 07985
Korea University Guro Hospital
Seoul, Seoul-teukbyeolsi [seoul], 08308
The Catholic University Of Korea St. Vincent's Hospital
Suwon, Kyǒnggi-do, 16247
Ajou University Hospital
Suwon, Kyǒnggi-do, 16499
About this study
Official title: A PHASE 3 STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) PREFUSION F SUBUNIT VACCINE IN OLDER ADULTS IN KOREA
The goal of this clinical trial is to quantify the immune response in older Korean adults after a RSVpreF vaccination. It will also learn about the safety and tolerability of RSVpreF vaccination. The main questions it aims to answer are:
What local reactions and systemic events do participants have after a RSVpreF vaccination? What medical problems do participants have after a RSVpreF vaccination? Researchers will compare RSVpreF to a placebo (a look-alike substance that contains no RSVpreF) to see if RSVpreF is safe and well tolerated. It will also examine the change in antibody levels (immune responses) before and after vaccination.
Read more
Participants will:
Receive the RSVpreF vaccination or a placebo injection once at Visit 1. Visit the clinic a month later for a checkup and tests. Receive a phone call 1 week after vaccination, and 2 months after vaccination, for health checks.
Keep a diary of their symptoms for 7 days after vaccination.
Read the detailed description
This is a Phase 3, randomized, double-blinded, placebo-controlled, multicenter trial to describe the safety, tolerability, and immunogenicity of bivalent RSVpreF in adults 60 years of age and older in Korea.
The study duration is approximately 2 months. 4 study visits are required and are comprised of 2 scheduled clinic visits and 2 scheduled telephone calls.
Approximately 360 study-eligible participants will be randomized to receive either the 120-µg dose of RSVpreF or placebo in a 2:1 ratio.
After screening and confirmation of eligibility, a prevaccination blood sample will be collected for immunogenicity assessments and a single dose of study intervention (RSVpreF or placebo) will be administered.
Participants will report daily reactogenicity data using an electronic device for 7-days or until resolution.
Participants will return approximately 1 month later for a follow-up blood draw for immunogenicity assessments and collection of safety information.
A telephone follow-up visit will be conducted approximately 1 week after vaccination to review reactogenicity and approximately 2 months after vaccination to collect safety information.
For all participants, adverse events (AEs) will be collected from informed consent through 1 month following study intervention administration. Serious adverse events (SAEs) newly diagnosed chronic medical conditions (NDCMCs), and adverse events of special interest (AESIs) will be collected from informed consent throughout study participation.
- Conditions
- Respiratory Syncytial Virus
- Being tested
- RSVpreF Vaccine, Placebo
- Keywords
- Respiratory tract infection, RSV, Respiratory Syncytial Virus, Vaccine, Older adults
- Medical subject headings
- Respiratory Tract Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RSVpreF VaccineBiological
RSV Vaccine 120 mcg
PlaceboOther
Placebo
| Study group | Role | What they receive |
|---|---|---|
| RSVpreF | Experimental | Not described Receives: Biological: RSVpreF Vaccine |
| Placebo | Placebo comparator | Not described Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants With Local Reactions Within 7 Days After Vaccination
Local reactions included redness, swelling and pain at injection site. Redness and swelling were measured and recorded in measuring device units. 1 measuring device unit=0.5 centimeter (cm). Redness and swelling were graded as mild: > 2.0 cm to 5.0 cm, moderate: > 5.0 cm to 10.0 cm, severe: >10.0 cm. Pain at injection site was graded as mild: did not interfere with activity, moderate: interfered with activity, severe: prevented daily activity. Any local reaction: any redness, any swelling, or pain at the injection site of at least mild severity. Exact 2-sided 95% confidence interval (CI) was based on the Clopper and Pearson method.
Measured: From Day 1 to Day 7 after vaccination
Percentage of Participants With Systemic Events Within 7 Days After Vaccination
Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. Fever defined as oral temperature >=38.0 degrees Celsius (deg C) and categorized as mild: >=38.0 to 38.4 deg C, moderate: >38.4 to 38.9 deg C, severe: >38.9 to 40.0 deg C, and Grade 4: >40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: >2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity. Exact 2-sided 95% CI was based on the Clopper and Pearson method.
Measured: From Day 1 to Day 7 after vaccination
Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination
An AE was any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Exact 2-sided 95% CI was based on the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were reported in this outcome measure.
Measured: From vaccination on Day 1 up to 1 month after vaccination
Percentage of Participants With Serious Adverse Events (SAEs) From Vaccination Throughout the Study
An SAE was defined as an AE that, at any dose met one of the following criteria: 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; was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or nonpathogenic; other significant medical events as judged by investigator. Exact 2-sided 95% CI was based on the Clopper and Pearson method.
Measured: From vaccination on Day 1 up to 2 months after vaccination
Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study
A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions. Exact 2-sided 95% CI was based on the Clopper and Pearson method.
Measured: From vaccination on Day 1 up to 2 months after vaccination
Geometric Mean Titer (GMT) of Neutralizing Titers (NTs) for RSV A and RSV B Before Vaccination
GMTs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the lower limit of quantification (LLOQ) were set to 0.5*LLOQ for analysis.
Measured: Before Vaccination
Geometric Mean Titer (GMT) of Neutralizing Titers (NTs) for RSV A and RSV B at 1 Month After Vaccination
GMTs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5*LLOQ for analysis.
Measured: 1 month after vaccination
Geometric Mean Fold Rise (GMFR) of Neutralizing Titers (NTs) for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination
Fold rises was defined as ratios of the results after vaccination to the results before vaccination. GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).
Measured: From before vaccination to 1 month after vaccination
Secondary outcomes (1)
Seroresponse Rates of Neutralizing Titers (NTs) for RSV A and RSV B at 1 Month After Vaccination
Seroresponse rate was defined as the percentage of participants with a postvaccination NT >=4 times the LLOQ if the baseline titer (before vaccination) was below the LLOQ; or a >=4-fold rise from baseline if the baseline titer was>=LLOQ. 95% CI was based on Clopper-Pearson method.
Measured: 1 month after vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Sep 2024
- Study start7 Oct 2024
- Primary completion3 Feb 2025
- Study completion3 Feb 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.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Respiratory Syncytial VirusStudies of the same condition, open and under way.
- More trials run by PfizerThe 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
- Model description
- Parallel
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 378 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06593587
- Sponsor's protocol ID
- C3671053
- Other IDs
- NCT06593587
- Status last verified
- Jan 2026
- First submitted
- 9 Sep 2024
- Last updated
- 9 Feb 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
Publications
Choi WS, Quan K, Baber JA, Jaques A, van Rensburg KJ, Li W, Cutler MW, Kalinina EV, Anderson AS, Swanson KA, Gurtman A, Munjal I; Jeongwol C3671053 Clinical Trial Group. A Randomized Phase 3 Study to Evaluate the Safety, Tolerability, and Immunogenicity of the Bivalent RSVpreF Vaccine in Older Adults in Korea. Vaccines (Basel). 2026 Sep 3;14(9):773. doi: 10.3390/vaccines14090773.
PubMed 42797593
Study at a glance
From the registry record, last updated by the sponsor on 9 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A PHASE 3 STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) PREFUSION F SUBUNIT VACCINE IN OLDER ADULTS IN KOREA
- ClinicalTrials.gov ID
- NCT06593587
- Acronym / sponsor ID
- C3671053
- Conditions
- Respiratory Syncytial Virus
- Keywords
- Respiratory tract infection, RSV, Respiratory Syncytial Virus, Vaccine, Older adults
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 378 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 7 Oct 2024 (actual)
- Primary completion
- 3 Feb 2025 (actual)
- Study completion
- 3 Feb 2025 (actual)
- First posted
- 19 Sep 2024 (actual)
- Results
- Posted 9 Feb 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this clinical trial is to quantify the immune response in older Korean adults after a RSVpreF vaccination. It will also learn about the safety and tolerability of RSVpreF vaccination. The main questions it aims to answer are:
What local reactions and systemic events do participants have after a RSVpreF vaccination? What medical problems do participants have after a RSVpreF vaccination? Researchers will compare RSVpreF to a placebo (a look-alike substance that contains no RSVpreF) to see if RSVpreF is safe and well tolerated. It will also examine the change in antibody levels (immune responses) before and after vaccination.
Participants will:
Receive the RSVpreF vaccination or a placebo injection once at Visit 1. Visit the clinic a month later for a checkup and tests. Receive a phone call 1 week after vaccination, and 2 months after vaccination, for health checks.
Keep a diary of their symptoms for 7 days after vaccination.
Detailed description
This is a Phase 3, randomized, double-blinded, placebo-controlled, multicenter trial to describe the safety, tolerability, and immunogenicity of bivalent RSVpreF in adults 60 years of age and older in Korea.
The study duration is approximately 2 months. 4 study visits are required and are comprised of 2 scheduled clinic visits and 2 scheduled telephone calls.
Approximately 360 study-eligible participants will be randomized to receive either the 120-µg dose of RSVpreF or placebo in a 2:1 ratio.
After screening and confirmation of eligibility, a prevaccination blood sample will be collected for immunogenicity assessments and a single dose of study intervention (RSVpreF or placebo) will be administered.
Participants will report daily reactogenicity data using an electronic device for 7-days or until resolution.
Participants will return approximately 1 month later for a follow-up blood draw for immunogenicity assessments and collection of safety information.
A telephone follow-up visit will be conducted approximately 1 week after vaccination to review reactogenicity and approximately 2 months after vaccination to collect safety information.
For all participants, adverse events (AEs) will be collected from informed consent through 1 month following study intervention administration. Serious adverse events (SAEs) newly diagnosed chronic medical conditions (NDCMCs), and adverse events of special interest (AESIs) will be collected from informed consent throughout study participation.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Parallel
| Arm | Type | Receives |
|---|---|---|
| RSVpreF | Experimental | Biological: RSVpreF Vaccine |
| Placebo | Placebo comparator | Other: Placebo |
Who may qualify
- Ages
- 60 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Participants 60 years of age or older at Visit 1
- Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study.
- Healthy participants with preexisting 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.
- Participants who are willing and able to comply with all scheduled visits, investigational plan, laboratory tests, frequent symptom assessment by mobile device application (e-diary), and other study procedures.
- Participants who are ambulatory and live in the community, or in assisted-living or long-term care residential facilities that provide minimal assistance, such that the participant is primarily responsible for self-care and activities of daily living (ADL).
Key exclusion criteria (16 listed)
- A confirmed diagnosis of RSV infection ≤180 days before study intervention administration.
- Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular (IM) injection.
- Prior history of any subtype of Guillain-Barré syndrome (GBS) of any etiology.
- History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s) or any related vaccine.
- Serious chronic disorder, including metastatic malignancy, end-stage renal disease with or without dialysis, clinically unstable cardiac disease, or any other disorder that, in the investigator's opinion, excludes the participant from participating in the study.
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 |
|---|---|---|
| RSVpreF VaccineRSV Vaccine 120 mcg | Biological | RSVpreF |
| PlaceboPlacebo | Other | Placebo |
Primary outcome
Percentage of Participants With Local Reactions Within 7 Days After Vaccination
Time frame: From Day 1 to Day 7 after vaccination
Local reactions included redness, swelling and pain at injection site. Redness and swelling were measured and recorded in measuring device units. 1 measuring device unit=0.5 centimeter (cm). Redness and swelling were graded as mild: > 2.0 cm to 5.0 cm, moderate: > 5.0 cm to 10.0 cm, severe: >10.0 cm. Pain at injection site was graded as mild: did not interfere with activity, moderate: interfered with activity, severe: prevented daily activity. Any local reaction: any redness, any swelling, or pain at the injection site of at least mild severity. Exact 2-sided 95% confidence interval (CI) was based on the Clopper and Pearson method.
Percentage of Participants With Systemic Events Within 7 Days After Vaccination
Time frame: From Day 1 to Day 7 after vaccination
Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. Fever defined as oral temperature >=38.0 degrees Celsius (deg C) and categorized as mild: >=38.0 to 38.4 deg C, moderate: >38.4 to 38.9 deg C, severe: >38.9 to 40.0 deg C, and Grade 4: >40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: >2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity. Exact 2-sided 95% CI was based on the Clopper and Pearson method.
Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination
Time frame: From vaccination on Day 1 up to 1 month after vaccination
An AE was any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Exact 2-sided 95% CI was based on the Clopper and Pearson method. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were reported in this outcome measure.
Percentage of Participants With Serious Adverse Events (SAEs) From Vaccination Throughout the Study
Time frame: From vaccination on Day 1 up to 2 months after vaccination
An SAE was defined as an AE that, at any dose met one of the following criteria: 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; was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or nonpathogenic; other significant medical events as judged by investigator. Exact 2-sided 95% CI was based on the Clopper and Pearson method.
Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study
Time frame: From vaccination on Day 1 up to 2 months after vaccination
A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions. Exact 2-sided 95% CI was based on the Clopper and Pearson method.
Geometric Mean Titer (GMT) of Neutralizing Titers (NTs) for RSV A and RSV B Before Vaccination
Time frame: Before Vaccination
GMTs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the lower limit of quantification (LLOQ) were set to 0.5*LLOQ for analysis.
Geometric Mean Titer (GMT) of Neutralizing Titers (NTs) for RSV A and RSV B at 1 Month After Vaccination
Time frame: 1 month after vaccination
GMTs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution). Assay results below the LLOQ were set to 0.5*LLOQ for analysis.
Geometric Mean Fold Rise (GMFR) of Neutralizing Titers (NTs) for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination
Time frame: From before vaccination to 1 month after vaccination
Fold rises was defined as ratios of the results after vaccination to the results before vaccination. GMFRs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of fold rises and the corresponding CIs (based on the Student t distribution).
1 secondary outcome
Seroresponse Rates of Neutralizing Titers (NTs) for RSV A and RSV B at 1 Month After Vaccination
Time frame: 1 month after vaccination
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Feb 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 42797593Choi WS, Quan K, Baber JA, Jaques A, van Rensburg KJ, Li W, Cutler MW, Kalinina EV, Anderson AS, Swanson KA, Gurtman A, Munjal I; Jeongwol C3671053 Clinical Trial Group. A Randomized Phase 3 Study to Evaluate the Safety, Tolerability, and Immunogenicity of the Bivalent RSVpreF Vaccine in Older Adults in Korea. Vaccines (Basel). 2026 Sep 3;14(9):773. doi: 10.3390/vaccines14090773.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
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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.
Pfizer CT.gov Call Center study director
Pfizer
16 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing RSVpreF Vaccine in people with Respiratory Syncytial Virus, run by Pfizer at 16 sites in South Korea.
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 8 inclusion and 16 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 9 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 16 sites in South Korea. 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. Some participants in this study may receive a placebo. 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 9 Feb 2026). 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?
Percentage of Participants With Local Reactions Within 7 Days After Vaccination (time frame: From Day 1 to Day 7 after vaccination). The study lists 8 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 NCT06593587, 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 9 Feb 2026.