Respiratory Syncytial Virus (RSV)Phase 3AmélieNCT06473519

A Study to Assess Safety, Tolerability and Immunogenicity of RSVpreF From Multidose Vials in Healthy Female Adults.

A Phase 3 study testing RSVpreF MDV and RSVpreF SDV in people with Respiratory Syncytial Virus (RSV), run by Pfizer at 6 sites in United States.

Completed

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

Official record

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Trial summary

Respiratory Syncytial Virus (RSV) is a common type of virus (germ) that can cause severe illness, where medical help is needed. RSV can lead to airway diseases in all ages. Vaccines help your body make antibodies. These antibodies help fight against diseases. This is called an immune response. Read more about this study

Who is it for?: Ages 18 to 49 years, women onlyHealthy volunteers can take part
Conditions the study is for: Respiratory Syncytial Virus (RSV)
What is being tested?: RSVpreF MDV and RSVpreF SDV
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 453 participants
Where: 6 sitesUnited States
Study dates: 24 Jun 2024to 20 Sep 2024
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 18 to 49 years
Women only
Healthy volunteers accepted
Adult

Who may be able to join

Healthy nonpregnant, nonbreastfeeding females 18 through 49 years of age at Visit 1 (Day 1).
Willing and able to comply with all scheduled visits, investigational plan, lifestyle considerations, and other study procedures.
Available for the duration of the study and can be contacted by telephone during study participation.
Capable of giving signed informed consent as described in the protocol which includes compliance with the requirements and restrictions listed in the ICD and in the protocol.

Who cannot join

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.
History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the vaccines being administered in the study.
Immunocompromised participants with known or suspected immunodeficiency, as determined by history, laboratory tests, and/or physical examination.
History or active autoimmune disease, including but not limited to systemic or cutaneous lupus erythematosus, autoimmune arthritis/rheumatoid arthritis, Guillain-Barré syndrome, multiple sclerosis, Sjögren's syndrome, idiopathic thrombocytopenia purpura, glomerulonephritis, autoimmune thyroiditis, giant cell arteritis (temporal arteritis), psoriasis, and insulin-dependent diabetes mellitus (type 1).
Bleeding diathesis or any condition that would, in the opinion of the investigator, contraindicate intramuscular injection.
Previous vaccination with any licensed or investigational RSV vaccine, or planned receipt of a nonstudy RSV vaccine throughout the study.

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Receipt of chronic systemic treatment with immunosuppressant medications (including cytotoxic agents or systemic corticosteroids), or radiotherapy, within 60 days before enrollment through conclusion of the study.
Receipt of blood/plasma products or immunoglobulin within 60 days before study intervention administration or planned receipt throughout the study.
Current alcohol abuse or illicit drug use.
Individuals who are pregnant or breastfeeding.
Participation in other studies involving an investigational product within 28 days prior to study entry and/or during study participation. Participation in purely observational studies is acceptable.
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.

Trial locations and contacts

6 sites in 1 country.

City, postcode or hospital

6 sites in 1 country

United States6 sites

Clinical Research Prime
Idaho Falls, Idaho, 83404
Clinical Research Prime Rexburg
Rexburg, Idaho, 83440
Clinical Trials of Texas, LLC dba Flourish Research
San Antonio, Texas, 78229
Qps-Mra, Llc
South Miami, Florida, 33143
Headlands Research - Detroit
Southfield, Michigan, 48034
Clinical Research Atlanta
Stockbridge, Georgia, 30281

Other trials in United States

About this study

Official title: A PHASE 3, RANDOMIZED, OPEN-LABEL TRIAL TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) PREFUSION F SUBUNIT VACCINE FORMULATED IN MULTIDOSE VIALS IN HEALTHY FEMALE ADULTS

The purpose of this study is to learn about the safety, tolerability, and immunogenicity of a RSV vaccine called RSVpreF. RSVpreF comes either as:

a single dose in a container (called a vial),
or in a vial that holds multiple doses. A multidose vial contains more than one dose of RSVpreF. 2-Phenoxyethanol (2-PE) is a preservative to help prevent the growth of bacteria (germs). This study will compare RSVpreF with an added preservative called 2-phenoxyethanol (2-PE) from a multidose vial, to RSVpreF without an added preservative, from a single-dose vial.

This study is looking to enroll nonpregnant, nonbreastfeeding, healthy female participants.

Participants will need to visit the study clinic two times during the study. Participants will also have a final safety telephone call at the end of the study. All participants will receive a single shot of the study vaccine either from:

a multidose vial (with the preservative), or
from a single-dose vial (without the preservative) at the first study clinic visit.

Blood samples will be taken at the two study clinic visits. Each participant will take part in the study for around 6 weeks.

Conditions: Respiratory Syncytial Virus (RSV)
Being tested: RSVpreF MDV, RSVpreF SDV
Keywords: RSV infection, Multidose Vial (MDV), Single-dose Vial (SDV), 2-Phenoxyethanol (2-PE), Vaccines
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.

RSVpreF MDVBiological
RSVpreF with 2-PE formulated in an MDV
RSVpreF SDVBiological
RSVpreF without 2-PE formulated in an SDV

Study groups in NCT06473519
Study group	Role	What they receive
RSVpreF multidose vial (MDV)	Experimental	RSVpreF with 2-PE formulated in an MDV Receives: Biological: RSVpreF MDV
RSVpreF single-dose vial (SDV)	Experimental	RSVpreF without 2-PE formulated in an SDV Receives: Biological: RSVpreF SDV

What is being measured

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

Geometric Mean Titer (GMT) of Serum Neutralizing Titers (NTs) for Respiratory Syncytial Virus Subgroup A (RSV A) and Respiratory Syncytial Virus Subgroup B (RSV B) Before Vaccination
GMTs and corresponding 2-sided 95% confidence intervals (CIs) were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).
Measured: Before vaccination on Day 1
GMT and Geometric Mean Ratio (GMR) of Serum NTs for RSV A and RSV B at 1 Month After Vaccination
GMTs and 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). GMTs of NTs for RSV A and B were reported in the descriptive data section of this outcome measure. GMR each for RSV A and RSV B was calculated as ratio of NTs of RSVpreF (MDV) to RSVpreF (SDV) and was reported in the statistical analysis section of this outcome measure.
Measured: 1 month after Vaccination on Day 1
Percentage of Participants With Local Reactions Within 7 Days After Vaccination
Local reactions included redness, swelling and pain at injection site, reported in the electronic diary (e-diary) and the participant-reported reactogenicity (PARREACT) case report form (CRF). Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit= 0.5 centimeter (cm) and graded as mild: >2.0 to 5.0 cm, moderate: >5.0 to 10.0 cm, severe: >10.0 cm, Grade 4: necrosis (redness and swelling) or exfoliative dermatitis (redness). Pain at injection site was graded as mild: did not interfere with activity, moderate: interfered with activity, severe: prevented daily activity, Grade 4: emergency room visit or hospitalization for severe pain at injection site.
Measured: Day 1 through 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, recorded in the e-diary and PARREACT CRF. Fever measured in degree Celsius and ranged: mild (38.0 - 38.4); moderate (38.5 - 38.9); severe (39.0 - 40.0); Grade 4: >40.0. Fatigue, headache, nausea, muscle and joint pain graded as: mild (didn't interfere with activity); moderate (some interference with activity); severe (prevented daily routine activity); Grade 4 [emergency room (ER) visit or hospitalization). Vomiting graded as: mild (1-2 times in 24 hours[h]); moderate (>2 times in 24h); severe (required intravenous hydration); Grade 4 (ER visit or hospitalization). Diarrhea graded as: mild (2-3 loose stools in 24h); moderate (4-5 loose stools in 24h); severe (6 or more loose stools in 24h); Grade 4 (ER visit or hospitalization).
Measured: Day 1 through Day 7 after Vaccination
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Vaccination
An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention were included in evaluation of this outcome measure. AEs included both serious AEs (SAEs) and all non-SAEs. Events collected by systematic assessment (local reactions and systemic events) were excluded from evaluation.
Measured: Within 1 Month after Vaccination
Percentage of Participants With SAEs Throughout the Study
An AEs was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more 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 and other important medical events per protocol of the study. Events collected by systematic assessment (local reactions and systemic events) were excluded from evaluation.
Measured: Within 42 to 49 days after Vaccination on Day 1 (maximum up to 1.6 months)

Secondary outcomes (1)

Percentage of Participants Achieving Seroresponse for RSV A and RSV B of Serum NTs at 1 Month After Vaccination
Seroresponse was defined as achieving a >=4-fold rise from baseline (before vaccination) if the baseline measurement was above the lower limit of quantification (LLOQ). If the baseline measurement was below the LLOQ, a postvaccination assay result >=4*LLOQ was considered a seroresponse.
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.

24 Jun 202420 Sep 2024

First posted25 Jun 2024
Study start24 Jun 2024
Primary completion20 Sep 2024
Study completion20 Sep 2024

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 Virus (RSV)Studies 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
Masking: None (open label)
Enrolment: 453 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT06473519
Sponsor's protocol ID: C4841001
Other IDs: NCT06473519
Acronym: Amélie
Status last verified: Sep 2025
First submitted: 17 Jun 2024
Last updated: 25 Sep 2025
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

Sarwar UN, Baker JB, Pereira L, Pahud BA, Finley J, Strong D, Pagnussat S, Patel S, Liu Y, Shittu E, Anastasiou OE, Kalinina EV, Swanson KA, Anderson AS, Gurtman A, Munjal I. Safety and immunogenicity of bivalent RSVpreF vaccine formulated in a multidose vial in healthy female participants in the USA: a multicentre, randomised, open-label, noninferiority phase 3 study. EClinicalMedicine. 2026 Jan 29;92:103767. doi: 10.1016/j.eclinm.2026.103767. eCollection 2026 Feb.
PubMed 41660362

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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All Respiratory Syncytial Virus (RSV) trials

Study at a glance

From the registry record, last updated by the sponsor on 25 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A PHASE 3, RANDOMIZED, OPEN-LABEL TRIAL TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) PREFUSION F SUBUNIT VACCINE FORMULATED IN MULTIDOSE VIALS IN HEALTHY FEMALE ADULTS
ClinicalTrials.gov ID: NCT06473519
Acronym / sponsor ID: Amélie / C4841001
Conditions: Respiratory Syncytial Virus (RSV)
Keywords: RSV infection, Multidose Vial (MDV), Single-dose Vial (SDV), 2-Phenoxyethanol (2-PE), Vaccines
Phase: Phase 3
Study type: Interventional
Recruitment status: Completed
Enrolment: 453 participants (actual)
Lead sponsor: PfizerIndustry (pharma, biotech, devices)
Study start: 24 Jun 2024 (actual)
Primary completion: 20 Sep 2024 (actual)
Study completion: 20 Sep 2024 (actual)
First posted: 25 Jun 2024 (actual)
Results: Posted 25 Sep 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

The purpose of this study is to learn about the safety, tolerability, and immunogenicity of a RSV vaccine called RSVpreF. RSVpreF comes either as:

a single dose in a container (called a vial),
or in a vial that holds multiple doses. A multidose vial contains more than one dose of RSVpreF. 2-Phenoxyethanol (2-PE) is a preservative to help prevent the growth of bacteria (germs). This study will compare RSVpreF with an added preservative called 2-phenoxyethanol (2-PE) from a multidose vial, to RSVpreF without an added preservative, from a single-dose vial.

This study is looking to enroll nonpregnant, nonbreastfeeding, healthy female participants.

a multidose vial (with the preservative), or
from a single-dose vial (without the preservative) at the first study clinic visit.

Blood samples will be taken at the two study clinic visits. Each participant will take part in the study for around 6 weeks.

Study design

Primary purpose: Prevention
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
RSVpreF multidose vial (MDV)	Experimental	Biological: RSVpreF MDVRSVpreF with 2-PE formulated in an MDV
RSVpreF single-dose vial (SDV)	Experimental	Biological: RSVpreF SDVRSVpreF without 2-PE formulated in an SDV

Who may qualify

Ages: 18 to 49 years
Sex: Female only
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (4 listed)

Healthy nonpregnant, nonbreastfeeding females 18 through 49 years of age at Visit 1 (Day 1).
Willing and able to comply with all scheduled visits, investigational plan, lifestyle considerations, and other study procedures.
Available for the duration of the study and can be contacted by telephone during study participation.
Capable of giving signed informed consent as described in the protocol which includes compliance with the requirements and restrictions listed in the ICD and in the protocol.

Key exclusion criteria (12 listed)

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.
History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the vaccines being administered in the study.
Immunocompromised participants with known or suspected immunodeficiency, as determined by history, laboratory tests, and/or physical examination.
History or active autoimmune disease, including but not limited to systemic or cutaneous lupus erythematosus, autoimmune arthritis/rheumatoid arthritis, Guillain-Barré syndrome, multiple sclerosis, Sjögren's syndrome, idiopathic thrombocytopenia purpura, glomerulonephritis, autoimmune thyroiditis, giant cell arteritis (temporal arteritis), psoriasis, and insulin-dependent diabetes mellitus (type 1).
Bleeding diathesis or any condition that would, in the opinion of the investigator, contraindicate intramuscular injection.

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 MDVRSVpreF with 2-PE formulated in an MDV	Biological	RSVpreF multidose vial (MDV)
RSVpreF SDVRSVpreF without 2-PE formulated in an SDV	Biological	RSVpreF single-dose vial (SDV)

Primary outcome

Geometric Mean Titer (GMT) of Serum Neutralizing Titers (NTs) for Respiratory Syncytial Virus Subgroup A (RSV A) and Respiratory Syncytial Virus Subgroup B (RSV B) Before Vaccination
Time frame: Before vaccination on Day 1
GMTs and corresponding 2-sided 95% confidence intervals (CIs) were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).
GMT and Geometric Mean Ratio (GMR) of Serum NTs for RSV A and RSV B at 1 Month After Vaccination
Time frame: 1 month after Vaccination on Day 1
GMTs and 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). GMTs of NTs for RSV A and B were reported in the descriptive data section of this outcome measure. GMR each for RSV A and RSV B was calculated as ratio of NTs of RSVpreF (MDV) to RSVpreF (SDV) and was reported in the statistical analysis section of this outcome measure.
Percentage of Participants With Local Reactions Within 7 Days After Vaccination
Time frame: Day 1 through Day 7 after Vaccination
Local reactions included redness, swelling and pain at injection site, reported in the electronic diary (e-diary) and the participant-reported reactogenicity (PARREACT) case report form (CRF). Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit= 0.5 centimeter (cm) and graded as mild: >2.0 to 5.0 cm, moderate: >5.0 to 10.0 cm, severe: >10.0 cm, Grade 4: necrosis (redness and swelling) or exfoliative dermatitis (redness). Pain at injection site was graded as mild: did not interfere with activity, moderate: interfered with activity, severe: prevented daily activity, Grade 4: emergency room visit or hospitalization for severe pain at injection site.
Percentage of Participants With Systemic Events Within 7 Days After Vaccination
Time frame: Day 1 through Day 7 after Vaccination
Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain, recorded in the e-diary and PARREACT CRF. Fever measured in degree Celsius and ranged: mild (38.0 - 38.4); moderate (38.5 - 38.9); severe (39.0 - 40.0); Grade 4: >40.0. Fatigue, headache, nausea, muscle and joint pain graded as: mild (didn't interfere with activity); moderate (some interference with activity); severe (prevented daily routine activity); Grade 4 [emergency room (ER) visit or hospitalization). Vomiting graded as: mild (1-2 times in 24 hours[h]); moderate (>2 times in 24h); severe (required intravenous hydration); Grade 4 (ER visit or hospitalization). Diarrhea graded as: mild (2-3 loose stools in 24h); moderate (4-5 loose stools in 24h); severe (6 or more loose stools in 24h); Grade 4 (ER visit or hospitalization).
Percentage of Participants With Adverse Events (AEs) Within 1 Month After Vaccination
Time frame: Within 1 Month after Vaccination
An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention were included in evaluation of this outcome measure. AEs included both serious AEs (SAEs) and all non-SAEs. Events collected by systematic assessment (local reactions and systemic events) were excluded from evaluation.
Percentage of Participants With SAEs Throughout the Study
Time frame: Within 42 to 49 days after Vaccination on Day 1 (maximum up to 1.6 months)
An AEs was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more 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 and other important medical events per protocol of the study. Events collected by systematic assessment (local reactions and systemic events) were excluded from evaluation.

1 secondary outcome

Percentage of Participants Achieving Seroresponse for RSV A and RSV B of Serum NTs at 1 Month After Vaccination
Time frame: 1 Month after Vaccination

Results and safety

Results posted to the registry on 25 Sep 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
RSVpreF (With Preservative, MDV)	224	220
RSVpreF (Without Preservative, SDV)	229	218

Primary outcome: Geometric Mean Titer (GMT) of Serum Neutralizing Titers (NTs) for Respiratory Syncytial Virus Subgroup A (RSV A) and Respiratory Syncytial Virus Subgroup B (RSV B) Before Vaccination

Time frame: Before vaccination on Day 1. Geometric mean (95% Confidence Interval). Unit: Titer

Measure	RSVpreF (With Preservative, MDV) n = 218	RSVpreF (Without Preservative, SDV) n = 216
RSV A	2362 (2118.7 to 2634.0)	2472 (2226.2 to 2744.8)
RSV B	2926 (2637.1 to 3245.7)	3172 (2866.2 to 3509.8)

Population analysed: Evaluable immunogenicity population (EIP): all eligible participants who received the study intervention to which they were randomized, had blood drawn for assay testing within the specified time frame (27 to 42 days after vaccination) for 1 month after vaccination, had at least 1 valid and determinate assay result at the 1-month follow-up visit, and had no major protocol violations. Here, "Number Analyzed" signifies participants evaluable for specified rows.

Primary outcome: GMT and Geometric Mean Ratio (GMR) of Serum NTs for RSV A and RSV B at 1 Month After Vaccination

Time frame: 1 month after Vaccination on Day 1. Geometric mean (95% Confidence Interval). Unit: Titer

Measure	RSVpreF (With Preservative, MDV) n = 218	RSVpreF (Without Preservative, SDV) n = 215
RSV A	33715 (30737.7 to 36981.4)	35131 (31949.4 to 38630.0)
RSV B	41471 (37505.0 to 45856.0)	45374 (40664.0 to 50628.8)

RSVpreF (With Preservative, MDV) vs RSVpreF (Without Preservative, SDV): Geometric mean ratio: 0.96 (95% CI 0.84 to 1.10)
RSVpreF (With Preservative, MDV) vs RSVpreF (Without Preservative, SDV): Geometric mean ratio: 0.91 (95% CI 0.79 to 1.06)

Population analysed: EIP: all eligible participants who received the study intervention to which they were randomized, had blood drawn for assay testing within the specified time frame (27 to 42 days after vaccination) for 1 month after vaccination, had at least 1 valid and determinate assay result at the 1-month follow-up visit, and had no major protocol violations. Here, "Overall Number of Participants Analyzed" signifies number of participants evaluable for this outcome measure.

Primary outcome: Percentage of Participants With Local Reactions Within 7 Days After Vaccination

Time frame: Day 1 through Day 7 after Vaccination. Number (95% Confidence Interval). Unit: Percentage of participants

Measure	RSVpreF (With Preservative, MDV) n = 223	RSVpreF (Without Preservative, SDV) n = 227
Redness: Any	9.4 (5.9 to 14.0)	15.9 (11.4 to 21.3)
Redness: Mild	5.8 (3.1 to 9.8)	9.3 (5.8 to 13.8)
Redness: Moderate	2.2 (0.7 to 5.2)	6.2 (3.4 to 10.1)
Redness: Severe	1.3 (0.3 to 3.9)	0.4 (0.0 to 2.4)
Redness: Grade 4	0 (0.0 to 1.6)	0 (0.0 to 1.6)
Swelling: Any	13.9 (9.6 to 19.1)	14.1 (9.8 to 19.3)
Swelling: Mild	8.1 (4.9 to 12.5)	8.8 (5.5 to 13.3)
Swelling: Moderate	4.9 (2.5 to 8.7)	4.8 (2.4 to 8.5)

Population analysed: Safety population consisted of all randomized participants who received study intervention.

Primary outcome: Percentage of Participants With Systemic Events Within 7 Days After Vaccination

Time frame: Day 1 through Day 7 after Vaccination. Number (95% Confidence Interval). Unit: Percentage of participants

Measure	RSVpreF (With Preservative, MDV) n = 223	RSVpreF (Without Preservative, SDV) n = 227
Fever: Any	3.1 (1.3 to 6.4)	1.8 (0.5 to 4.5)
Fever: Mild	1.8 (0.5 to 4.6)	0.9 (0.1 to 3.2)
Fever: Moderate	0.4 (0.0 to 2.5)	0.4 (0.0 to 2.5)
Fever: Severe	0.9 (0.1 to 3.2)	0.4 (0.0 to 2.5)
Fever: Grade 4	0 (0.0 to 1.7)	0 (0.0 to 1.6)
Fatigue: Any	47.5 (41.0 to 54.5)	46.7 (40.4 to 53.9)
Fatigue: Mild	20.6 (15.6 to 26.7)	21.1 (16.2 to 27.3)
Fatigue: Moderate	25.1 (19.7 to 31.5)	24.7 (19.4 to 31.1)

Population analysed: Safety population consisted of all randomized participants who received study intervention.

1 secondary outcome is reported in the full results.

Adverse events

Time frame: Systematic assessment (local reactions and systemic events): Day 1 through Day 7 after Vaccination; Non-systematic assessment (serious AEs and all-cause mortality): within 42 to 49 days after Vaccination on Day 1 (maximum up to 1.6 months), Other AEs: within 1 month after Vaccination. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
RSVpreF (With Preservative, MDV)	1 of 223 (0.4%)	169 of 223 (75.8%)	0 of 223
RSVpreF (Without Preservative, SDV)	2 of 227 (0.9%)	174 of 227 (76.7%)	0 of 227

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 25 Sep 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 41660362Sarwar UN, Baker JB, Pereira L, Pahud BA, Finley J, Strong D, Pagnussat S, Patel S, Liu Y, Shittu E, Anastasiou OE, Kalinina EV, Swanson KA, Anderson AS, Gurtman A, Munjal I. Safety and immunogenicity of bivalent RSVpreF vaccine formulated in a multidose vial in healthy female participants in the USA: a multicentre, randomised, open-label, noninferiority phase 3 study. EClinicalMedicine. 2026 Jan 29;92:103767. doi: 10.1016/j.eclinm.2026.103767. eCollection 2026 Feb.
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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Study to Learn About a Respiratory Syncytial Virus Vaccine in Children at High Risk of RSV Disease
Respiratory Syncytial Virus (RSV)
Active, not recruitingPhase 3
A Study on the Immune Response and Safety of Vaccine Against Respiratory Syncytial Virus Given to Chinese Adults 18 to 59 Years of Age at Increased Risk of Respiratory Syncytial Virus Disease
Respiratory Syncytial Virus Infections
Active, not recruitingPhase 1
A Phase 1 Study to Evaluate JCXH-108, an mRNA-based Vaccine Against RSV
Respiratory Syncytial Virus (RSV), Infectious Disease
RecruitingPhase 2
Immunogenicity of RSVPreF3 Vaccine in Immunocompromised Persons
Respiratory Syncytial Virus (RSV)
RecruitingObservational study
TARSILA Real-World Evidence Study
Respiratory Syncytial Virus (RSV), Maternal Immunization

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

6 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 MDV and RSVpreF SDV in people with Respiratory Syncytial Virus (RSV), run by Pfizer at 6 sites in United States.

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 4 inclusion and 12 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 25 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 6 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

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

What does this phase mean?

Phase 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 25 Sep 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?

Geometric Mean Titer (GMT) of Serum Neutralizing Titers (NTs) for Respiratory Syncytial Virus Subgroup A (RSV A) and Respiratory Syncytial Virus Subgroup B (RSV B) Before Vaccination (time frame: Before vaccination on Day 1). The study lists 6 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 NCT06473519, 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 25 Sep 2025.