Phase 3
N=859
A Follow-up Study to Describe the Safety of Study Participants Who Received RSVPreF3 Maternal Vaccination (Any Dose) or Controls From Previous RSV MAT Studies During Any Pregnancy Conceived Post Vaccination/Control
Respiratory Syncytial Virus Infections
Bottom Line
View on ClinicalTrials.gov: NCT05705440 ↗Enrolled (actual)
859
Serious AEs
17.8%
Results posted
Mar 2026
Primary outcome: Primary: Number of Maternal Participants With Pregnancy Outcomes From Conception Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies — 249; 120; 28; 14 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- RSVPreF3 vaccine (Biological); Control (Other)
- Age
- Pediatric, Adult · 9+ yrs
- Sex
- Female
- Sponsor
- GlaxoSmithKline
- Primary completion
- Jan 2025
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Number of Maternal Participants With Pregnancy Outcomes From Conception Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
249; 120; 28; 14; 1; 1 | — |
| PRIMARY Number of Maternal Participants With Pregnancy-related Adverse Events of Special Interest (AESIs) From Conception Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
2; 0; 3; 3; 12; 7 | — |
| PRIMARY Number of Infant Participants With AESIs From Birth Until Day 42 Post-birth of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
3; 0; 1; 0; 18; 5 | — |
| SECONDARY Number of Pregnancies With Pregnancy Outcomes From Conception Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
257; 123; 31; 16; 1; 1 | — |
| SECONDARY Number of Pregnancies With Pregnancy-related AESIs From Conception Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
12; 3; 10; 3; 2; 1 | — |
| SECONDARY Number of Infant Participants With AESIs From Birth Until Day 42 Post-birth of Any Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
4; 0; 1; 0; 20; 5 | — |
| SECONDARY Number of Pregnancies With Preterm Birth Event Data Stratified by Selected Risk Factors, From Day 1 Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
5; 1; 2; 3; 18; 6 | — |
| SECONDARY Number of Pregnancies With Preterm Birth Event Data Stratified by Age Group at Vaccination, From Day 1 Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
0; 0; 2; 0; 11; 2 | — |
| SECONDARY Number of Pregnancies With Preterm Birth Event Data Stratified by Pre-pregnancy BMI, From Day 1 Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
10; 2; 163; 87; 1; 3 | — |
| SECONDARY Number of Pregnancies With Preterm Birth Event Data Stratified by Race, From Day 1 Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
0; 1; 5; 8; 6; 0 | — |
| SECONDARY Number of Pregnancies With Preterm Birth Event Data Stratified by Multiple Gestation Pregnancy, From Day 1 Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
22; 7; 242; 125; 1; 0 | — |
| SECONDARY Number of Pregnancies With Preterm Birth Event Data Stratified by Geographic Region, From Day 1 Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
6; 3; 93; 51; 6; 0 | — |
| SECONDARY Number of Pregnancies With Preterm Birth Event Data Stratified by Economic Region, From Day 1 Until Day 42 Post-delivery of Any Pregnancy Conceived by Maternal Participants Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
13; 3; 66; 38; 10; 4 | — |
| SECONDARY Number of Maternal Participants With Preterm Birth Event Data Stratified by Selected Risk Factors, From Day 1 Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
5; 1; 2; 3; 17; 6 | — |
| SECONDARY Number of Maternal Participants With Preterm Birth Event Data Stratified by Age Group at Vaccination, From Day 1 Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
0; 0; 2; 0; 11; 2 | — |
| SECONDARY Number of Maternal Participants With Preterm Birth Event Data Stratified by Pre-pregnancy BMI Group, From Day 1 Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
10; 2; 161; 87; 1; 3 | — |
| SECONDARY Number of Maternal Participants With Preterm Birth Event Data Stratified by Race, From Day 1 Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
0; 1; 5; 8; 6; 0 | — |
| SECONDARY Number of Maternal Participants With Preterm Birth Event Data Stratified by Multiple Gestation Pregnancy, From Day 1 Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
22; 7; 242; 125; 0; 0 | — |
| SECONDARY Number of Maternal Participants With Preterm Birth Event Data Stratified by Geographic Region, From Day 1 Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
5; 3; 90; 50; 6; 0 | — |
| SECONDARY Number of Maternal Participants With Preterm Birth Event Data Stratified by Economic Region, From Day 1 Until Day 42 Post-delivery of the First Pregnancy Conceived Within 2 Years Post-vaccination Received in Prior RSV MAT Studies |
13; 3; 66; 38; 9; 4 | — |
Summary
The purpose of this follow-up study was to describe the safety in subsequent pregnancies in participants who were previously administered the RSVPreF3 maternal vaccine or control during any prior RSV MAT study.
The study participants enrolled in this follow-up study received RSVPreF3 maternal vaccination (any dose) or controls during the following prior RSV MAT studies: RSV MAT-001 (NCT03674177), RSV MAT-004 (NCT04126213), RSV MAT-010 (NCT05045144), RSV MAT-011 (NCT04138056), RSV MAT-009 (NCT04605159), RSV MAT-012 (NCT04980391) and RSV MAT-039 (NCT05169905).
No intervention was administered in this study. The exposure was the intervention (either RSVPreF3 vaccine or control) received by the study participants in the abovementioned prior RSV MAT studies.
Eligibility Criteria
Inclusion Criteria
Retrospective cohort
Adult/Adolescent Participant:
- Adult/Adolescent study participant from any of the prior RSV MAT studies who have either received RSV MAT vaccine or control (placebo, Tdap or influenza vaccine).
- Study participant:
- who has reached 2 years+2 months post vaccine/control prior to/at enrolment or
- who has not reached 2 years+2 months post vaccine/control prior to/at enrolment but is a Woman of Nonchildbearing Potential (WONCBP) at study enrolment, or recipient of bilateral tubal ligation prior to study enrolment.
- Study participant with any pregnancy conceived post vaccination/control, that has reached Day 42 post-delivery prior to/at enrollment.
- Provide signed and dated informed consent form.
- Be willing to comply with all study requirements and be available for the duration of the study.
Infant Participant:
- Participant live born as the result of a pregnancy followed in an adult/adolescent participant in this study.
- Signed and dated informed consent form obtained from the participant's parent(s)/LAR(s) prior to performance of any study-specific procedure.
Prospective cohort
Adult/Adolescent Participant:
- Adult/adolescent study participant from any of the prior RSV MAT studies who have either received RSV MAT vaccine or control (placebo, Tdap or influenza vaccine).
- Study participant:
- who has not reached 2 years+2 months post vaccine/control prior to/at enrollment or
- who has reached at least 2 years+2 months post vaccine/control but has an ongoing pregnancy (prior to Day 42 post-delivery) at enrollment. Participants who have reached 2 years post-vaccine/control before enrollment but are pregnant at enrollment will be enrolled and followed until Day 42 post-delivery for the pregnancy ongoing at enrollment.
- Female participants of childbearing potential.
- Provide signed and dated informed consent form.
- Be willing to comply with all study procedures and be available for the duration of the study.
Infant Participant:
- Participant live born as the result of a pregnancy followed in an adolescent/adult participant in this study.
- Participant's parent(s)/LAR(s), in the opinion of the investigator, can and will comply with the requirements of the protocol.
- Signed and dated informed consent form obtained from the participant's parent(s)/LAR(s) prior to performance of any study-specific procedure.
Exclusion Criteria
Adult/adolescent participant otherwise eligible for the prospective cohort:
- Woman of Nonchildbearing Potential (WONCBP) at study enrollment, or recipient of bilateral tubal ligation prior to study enrollment, if she has not conceived a pregnancy post-vaccine/control and does not plan to use any additional measures to attempt to conceive a pregnancy (e.g., sterilization reversal or IVF).
Infant participant:
- Child in care.
Data sourced from ClinicalTrials.gov (NCT05705440). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.