A Phase 3 Study of Revaccination in Subsequent Pregnancies With Bivalent RSV Vaccine and Duration of Protection of a Single Dose

NCT ID: NCT06866405

Last Updated: 2025-11-12

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE3

Total Enrollment

550 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-04-16

Study Completion Date

2028-02-24

Brief Summary

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This study aims to check how safe and well-tolerated a second dose of RSVpreF is when given during later pregnancies, and to see how long the immunity lasts from a single dose given during a previous pregnancy by examining the blood of nonpregnant participants who had the vaccine before.

Detailed Description

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This study will include pregnant participants and their unborn babies (Cohort 1 and Cohort 2) and non-pregnant participants (Cohort 3), as described below:

* Cohort 1- Pregnant participants who had previously received RSVpreF as part of a Pfizer clinical trial and have antibody data available from that trial will get a second dose of RSVpreF.
* Cohort 2- Pregnant participants who received the RSVpreF in a previous pregnancy, either through commercial means with Abrysvo® or as part of a Pfizer clinical trial, will be randomly chosen to get either one dose of the RSVpreF or one dose of a placebo. This applies to those who do not have antibody data available from the earlier trial.

For both groups of pregnant participants, the study will look at how safe and well-tolerated the vaccine is during pregnancy, as well as how the body responds to it.

Infants will be monitored for six months after birth to check safety and antibodies level.

• Cohort 3- Nonpregnant participants who received RSVpreF during a previous pregnancy as part of an earlier clinical trial will have blood samples taken to see how well their immune response has persisted over time. Participants will not receive any vaccine.

Conditions

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RSV Infection

Keywords

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Pregnancy RSV vaccine RSV Maternal immunization

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

PREVENTION

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors
Blinding only applies to Cohort 2 of the study.

Study Groups

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RSVpreF

Group Type EXPERIMENTAL

RSVpreF

Intervention Type BIOLOGICAL

Single Dose

Placebo

Group Type PLACEBO_COMPARATOR

Placebo

Intervention Type BIOLOGICAL

Single Dose

Interventions

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RSVpreF

Single Dose

Intervention Type BIOLOGICAL

Placebo

Single Dose

Intervention Type BIOLOGICAL

Eligibility Criteria

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Inclusion Criteria

* Women aged 18 to 49 who are pregnant, between 24 and 36 weeks along, and expecting one baby without known risks for complications can participate.
* Had the RSVpreF or Abrysvo vaccine during a previous pregnancy.
* Had an ultrasound scan at 18 weeks or later during their current pregnancy, with no major fetal problems detected.
* Based on their medical history, physical check-up, and the doctor's judgment, they are found suitable to join the study.
* Agrees to let their baby take part in the study and gives their permission.
* Able to sign a consent form, agreeing to follow the rules and conditions of the study.


* Have already received one dose of the RSVpreF vaccine during their previous pregnancy as part of the Pfizer clinical trial, and the results from that time can be used for this study.
* Able to sign a consent form, agreeing to follow the rules and requirements of the study.

Exclusion Criteria

* Received any approved or experimental RSV vaccine since their previous pregnancy.
* Has a pre-pregnancy body mass index (BMI) over 40 kg/m2.
* History of a severe bad reaction to a vaccine or a serious allergic reaction (like anaphylaxis) to any ingredient in the study vaccine or a similar vaccine.
* Current pregnancy problems or issues at the time of giving consent.
* Previous pregnancy issues or problems at the time of giving consent.

Infant Participants

* Proof that the parent(s) or legal guardian(s) has signed and dated a consent form.
* Parent(s) or legal guardian(s) must agree to attend scheduled visits and follow the study plan, including laboratory tests and other procedures.


* Received any approved or experimental RSV vaccine after participating in the Pfizer clinical trial.
* Taking part in other studies with new drugs within 28 days before giving consent or during the study period.
Minimum Eligible Age

0 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Pfizer

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Pfizer CT.gov Call Center

Role: STUDY_DIRECTOR

Pfizer

Locations

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Center for Research in Women's Health

Birmingham, Alabama, United States

Site Status RECRUITING

Children's of Alabama

Birmingham, Alabama, United States

Site Status RECRUITING

University of Alabama at Birmingham - School of Medicine

Birmingham, Alabama, United States

Site Status RECRUITING

University of Alabama at Birmingham Women & Infants Center

Birmingham, Alabama, United States

Site Status RECRUITING

USA Health Children's and Women's Hospital

Mobile, Alabama, United States

Site Status RECRUITING

USA Health Strada Patient Care Center

Mobile, Alabama, United States

Site Status RECRUITING

Ronald Reagan UCLA Medical Center (inpatient hospital)

Los Angeles, California, United States

Site Status RECRUITING

UCLA (outpatient clinic)

Los Angeles, California, United States

Site Status RECRUITING

UCLA Clinical and Translational Research Center (research clinic)

Los Angeles, California, United States

Site Status RECRUITING

UCLA

Los Angeles, California, United States

Site Status RECRUITING

Lucile Packard Children's Hospital-Labor and Delivery Unit

Palo Alto, California, United States

Site Status RECRUITING

Stanford Obstetrics Clinic

Palo Alto, California, United States

Site Status RECRUITING

Stanford University Medical Center

Palo Alto, California, United States

Site Status RECRUITING

Stanford University

Palo Alto, California, United States

Site Status RECRUITING

Anschutz Health Sciences Building (AHSB)

Aurora, Colorado, United States

Site Status RECRUITING

Children's Hospital Colorado

Aurora, Colorado, United States

Site Status RECRUITING

CU Research Pharmacy

Aurora, Colorado, United States

Site Status RECRUITING

University of Colorado AO1 UCH

Aurora, Colorado, United States

Site Status RECRUITING

University of Colorado Hospital Inpatient Pavilion

Aurora, Colorado, United States

Site Status RECRUITING

University of Colorado Hospital Outpatient Pavilion

Aurora, Colorado, United States

Site Status RECRUITING

University of Colorado Research II Building

Aurora, Colorado, United States

Site Status RECRUITING

Citadelle Clinical Research

North Miami Beach, Florida, United States

Site Status NOT_YET_RECRUITING

Emerald Coast OBGYN Clinical Research

Panama City, Florida, United States

Site Status RECRUITING

Emerald Coast Pediatrics

Panama City, Florida, United States

Site Status RECRUITING

HCA Florida Gulf Coast Hospital

Panama City, Florida, United States

Site Status RECRUITING

Emerald Coast Pediatrics

Panama City Beach, Florida, United States

Site Status RECRUITING

Advanced Specialty Research

Boise, Idaho, United States

Site Status RECRUITING

Saint Alphonsus Regional Medical Center

Boise, Idaho, United States

Site Status RECRUITING

St. Luke's Boise Medical Center

Boise, Idaho, United States

Site Status RECRUITING

Clinical Research Prime

Idaho Falls, Idaho, United States

Site Status RECRUITING

Saint Alphonsus Medical Center

Nampa, Idaho, United States

Site Status RECRUITING

St. Luke's Nampa Medical Center

Nampa, Idaho, United States

Site Status RECRUITING

Accellacare - McFarland

Ames, Iowa, United States

Site Status RECRUITING

Mary Greeley Medical Center

Ames, Iowa, United States

Site Status RECRUITING

University of Kansas Medical Center

Kansas City, Kansas, United States

Site Status RECRUITING

Velocity Clinical Research, Lafayette

Lafayette, Louisiana, United States

Site Status RECRUITING

Velocity Clinical Research - New Orleans

New Orleans, Louisiana, United States

Site Status RECRUITING

Boston Medical Center

Boston, Massachusetts, United States

Site Status RECRUITING

Velocity Clinical Research, Gulfport

Gulfport, Mississippi, United States

Site Status RECRUITING

Boeson Research GTF

Great Falls, Montana, United States

Site Status RECRUITING

OBGYN Associates

Great Falls, Montana, United States

Site Status RECRUITING

Boeson Research KAL

Kalispell, Montana, United States

Site Status RECRUITING

Heart & Hands Midwifery

Kalispell, Montana, United States

Site Status RECRUITING

Boeson Research MSO

Missoula, Montana, United States

Site Status RECRUITING

Origin Health

Missoula, Montana, United States

Site Status RECRUITING

Velocity Clinical Research, Grand Island

Grand Island, Nebraska, United States

Site Status RECRUITING

Velocity Clinical Research, Norfolk

Norfolk, Nebraska, United States

Site Status RECRUITING

Presbyterian Hospital

Albuquerque, New Mexico, United States

Site Status RECRUITING

UNM Hospital

Albuquerque, New Mexico, United States

Site Status RECRUITING

Velocity Clinical Research, Albuquerque

Albuquerque, New Mexico, United States

Site Status RECRUITING

Lovelace Women's Hospital

Albuquerque, New Mexico, United States

Site Status RECRUITING

Duke Regional Hospital

Durham, North Carolina, United States

Site Status RECRUITING

Duke University - Main Hospital and Clinics

Durham, North Carolina, United States

Site Status RECRUITING

Duke University - Main Hospital and Clinics

Durham, North Carolina, United States

Site Status RECRUITING

Cincinnati Children's Hospital Medical Center

Cincinnati, Ohio, United States

Site Status RECRUITING

Prisma Health-Upstate

Greenville, South Carolina, United States

Site Status NOT_YET_RECRUITING

Prisma Health

Greenville, South Carolina, United States

Site Status NOT_YET_RECRUITING

Memorial Hermann Memorial City Hospital

Houston, Texas, United States

Site Status RECRUITING

The University of Texas Health Science Center at Houston

Houston, Texas, United States

Site Status RECRUITING

Helios Clinical Research - WEA

Weatherford, Texas, United States

Site Status RECRUITING

Medical City Weatherford

Weatherford, Texas, United States

Site Status RECRUITING

Weatherford OB/GYN Associates

Weatherford, Texas, United States

Site Status RECRUITING

University of Utah

Salt Lake City, Utah, United States

Site Status NOT_YET_RECRUITING

University of Utah Clinical Neuroscience Center

Salt Lake City, Utah, United States

Site Status NOT_YET_RECRUITING

University of Utah Hospital

Salt Lake City, Utah, United States

Site Status NOT_YET_RECRUITING

University of Utah

Salt Lake City, Utah, United States

Site Status NOT_YET_RECRUITING

Sentara Leigh Hospital

Norfolk, Virginia, United States

Site Status RECRUITING

The Group For Women - Kempsville Office

Norfolk, Virginia, United States

Site Status RECRUITING

Tidewater Physicians for Women

Norfolk, Virginia, United States

Site Status RECRUITING

WomensCare Center

Norfolk, Virginia, United States

Site Status RECRUITING

Virginia Physicians For Women (VPFW)

North Chesterfield, Virginia, United States

Site Status RECRUITING

Clinical Research Partners, LLC

Richmond, Virginia, United States

Site Status RECRUITING

Infusion Solutions, LLC

Richmond, Virginia, United States

Site Status RECRUITING

Seattle Children's Research Institute

Seattle, Washington, United States

Site Status RECRUITING

Seattle Children's Hospital

Seattle, Washington, United States

Site Status RECRUITING

University of Washington - Northwest

Seattle, Washington, United States

Site Status RECRUITING

University of Washington Medical Center - Montlake

Seattle, Washington, United States

Site Status RECRUITING

Fundación Respirar

Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina

Site Status RECRUITING

Clínica Mayo de Urgencias Médicas Cruz Blanca S.R.L

San Miguel de Tucumán, Tucumán Province, Argentina

Site Status RECRUITING

Instituto de Maternidad y Ginecología Nuestra Señora de las Mercedes

San Miguel de Tucumán, Tucumán Province, Argentina

Site Status RECRUITING

Centro de investigación Clínica OSECAC - Sede Jonas Salk

Buenos Aires, , Argentina

Site Status RECRUITING

Equipo Ciencia

Buenos Aires, , Argentina

Site Status NOT_YET_RECRUITING

Hospital Público Materno Infantil

Salta, , Argentina

Site Status NOT_YET_RECRUITING

Josha Research

Bloemfontein, Free State, South Africa

Site Status RECRUITING

University of Witwatersrand (WITS) - Vaccines and Infectious Diseases Analytics (VIDA)

Johannesburg, Gauteng, South Africa

Site Status RECRUITING

Wits RHI

Johannesburg, Gauteng, South Africa

Site Status RECRUITING

Into Research

Pretoria, Gauteng, South Africa

Site Status RECRUITING

Countries

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United States Argentina South Africa

Central Contacts

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Pfizer CT.gov Call Center

Role: CONTACT

Phone: 1-800-718-1021

Email: [email protected]

Related Links

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https://pmiform.com/clinical-trial-info-request?StudyID=C3671059

To obtain contact information for a study center near you, click here.

Other Identifiers

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Marguerite

Identifier Type: OTHER

Identifier Source: secondary_id

C3671059

Identifier Type: -

Identifier Source: org_study_id