The purpose of this study was to evaluate the safety, reactogenicity and immune response of a single intramuscular dose of the respiratory syncytial virus (RSV) maternal vaccine compared to placebo, when administered in the second or third trimester of pregnancy in women, 15 to 49 years of age (YOA), with high risk pregnancies and in the infants born to the vaccinated mothers. Following a recommendation from the Independent Data Monitoring Committee of NCT04605159 (RSV MAT 009), GSK made the decision to stop enrolment and vaccination in the study. Ongoing study participants at that time continued to be monitored as part of the study.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
384
Single dose of the RSV MAT vaccine reconstituted with NaCl solution, administered intramuscularly in the non-dominant arm, at Day 1.
Single dose of placebo, administered intramuscularly in the non-dominant arm, at Day 1.
GSK Investigational Site
Birmingham, Alabama, United States
GSK Investigational Site
Dothan, Alabama, United States
GSK Investigational Site
Mobile, Alabama, United States
GSK Investigational Site
Phoenix, Arizona, United States
GSK Investigational Site
Covington, Louisiana, United States
Percentage of Maternal Participants Reporting Any Solicited Administration Site Events
Assessed solicited administration site events included erythema, pain and swelling. Any pain = occurrence of the symptom regardless of intensity grade. Any erythema and swelling = symptom reported with a surface diameter greater than or equal to 20 millimeters.
Time frame: From Day 1 to Day 7 included
Percentage of Maternal Participants Reporting Any Solicited Systemic Events
Assessed solicited systemic events included abdominal pain, diarrhea, fatigue, headache, nausea, fever \[temperature equal to or above (\>=) 38 degrees Celsius (°C)/100.4 degrees Fahrenheit (°F), regardless of the location of measurement\] and vomiting. Any = occurrence of the adverse event regardless of intensity grade or relation to study vaccination.
Time frame: From Day 1 to Day 7 included
Percentage of Maternal Participants Reporting Any Unsolicited Adverse Events (AEs)
An unsolicited AE was defined as any AE reported in addition to those solicited during the clinical study. Also, any 'solicited' symptom with onset outside the specified period of follow-up for solicited symptoms was reported as an unsolicited AE. Any = occurrence of any unsolicited AE regardless of intensity grade or relation to vaccination.
Time frame: From Day 1 to Day 30 included
Percentage of Maternal Participants Reporting Any Serious Adverse Events (SAEs) From Day 1 up to 42 Days Post-delivery
An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect in the offspring of a study participant or resulted in abnormal pregnancy outcomes or in other situations that were considered serious per medical or scientific judgment. Any = occurrence of any SAE regardless of intensity grade or relation to vaccination.
Time frame: From Day 1 up to 42 days post-delivery, an average of 2 months
Number of Maternal Participants Reporting (S)AEs Leading to Study Withdrawal From Day 1 up to 42 Days Post-delivery
A participant was considered to have withdrawn from the study if no new study procedure had been performed or no new information had been collected for her since the date of withdrawal/last contact. (S)AEs leading to study withdrawal were (S)AEs identified by the investigator to cause participant withdrawal until the resolution of the event. These participant withdrawals were considered different from participant withdrawals for other reasons.
Time frame: From Day 1 up to 42 days post-delivery, an average of 2 months
Percentage of Maternal Participants Reporting Medically Attended Adverse Events (MAEs) From Day 1 up to 42 Days Post-delivery
An MAE was defined as an unsolicited AE for which the participant received medical attention such as hospitalization, or an emergency room visit, or visit to/by a health care provider.
Time frame: From Day 1 up to 42 days post-delivery, an average of 2 months
Percentage of Live Births With no Congenital Anomalies, Live Births With Minor Congenital Anomaly(Ies) and Live Births With at Least 1 Major Congenital Anomaly
The percentage of live births with no congenital anomalies, live births with minor congenital anomaly(ies) only and live births with at least 1 major congenital anomaly is reported.
Time frame: From Day 1 up to 42 days post-delivery, an average of 2 months
Percentage of Maternal Participants Reporting Pregnancy-related Adverse Events of Special Interest (AESIs) From Day 1 up to 42 Days Post-delivery
Pregnancy-related AESIs included preterm labor, provider-initiated preterm birth, premature preterm rupture of membranes, pre-eclampsia, pre-eclampsia with severe features including eclampsia, gestational hypertension and fetal growth restriction.
Time frame: From Day 1 up to 42 days post-delivery, an average of 2 months
Percentage of Maternal Participants Reporting Worsening of Pre-existing Medical Conditions and/or Obstetric Complications From Day 1 up to 42 Days Post-delivery
Worsening of pre-existing medical condition and/or obstetric complication was considered by the investigator, using clinical judgment and the following criteria: * Change in medication and/or medication dose. * Medically attended event in relation to pre-existing condition and/or obstetric complication that are outside the routine management of the condition/complication. * SAE and/or hospitalization in relation to pre-existing condition and/or obstetric complication.
Time frame: From Day 1 up to 42 days post-delivery, an average of 2 months
Percentage of Infant Participants Reporting Neonatal/Infant AESIs From Birth up to 42 Days Post-birth
Neonatal/infant AESIs included low birth weight (below \[\<\] 2500 grams), very low birth weight (\<1500 grams), extremely low birth weight (\<1000 grams), preterm birth (\<37 weeks of gestational age), small for gestational age (weight below 10th percentile for gestational age), congenital anomalies with internal structural defects and neonatal death in a preterm live birth (gestational age equal to or above \[\>=\] 28 and \<37 weeks).
Time frame: From birth up to 42 days post-birth, an average of 2 months
Percentage of Infant Participants Reporting Any SAEs From Birth up to 42 Days Post-birth
An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect or resulted in other situations that were considered serious per medical or scientific judgment. Any = occurrence of any SAE regardless of intensity grade or relation to vaccination.
Time frame: From birth up to 42 days post-birth, an average of 2 months
Number of Infant Participants Reporting (S)AEs Leading to Study Withdrawal From Birth up to 42 Days Post-birth
A participant was considered to have withdrawn from the study if no new study procedure had been performed or no new information had been collected for her since the date of withdrawal/last contact. (S)AEs leading to study withdrawal were (S)AEs identified by the investigator to cause participant withdrawal until the resolution of the event. These participant withdrawals were considered different from participant withdrawals for other reasons.
Time frame: From birth up to 42 days post-birth, an average of 2 months
Percentage of Infant Participants Reporting MAEs From Birth up to 42 Days Post-birth
An MAE was defined as an unsolicited AE for which the participants received medical attention such as hospitalization, or an emergency room visit, or visit to/by a health care provider.
Time frame: From birth up to 42 days post-birth, an average of 2 months
Percentage of Infant Participants Reporting Any SAEs From Birth up to 180 Days Post-birth
An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect or resulted in other situations that were considered serious per medical or scientific judgment. Any = occurrence of any SAE regardless of intensity grade or relation to vaccination.
Time frame: From birth up to 180 days post-birth
Number of Infant Participants Reporting (S)AEs Leading to Study Withdrawal From Birth up to 180 Days Post-birth
A participant was considered to have withdrawn from the study if no new study procedure had been performed or no new information had been collected for her since the date of withdrawal/last contact. (S)AEs leading to study withdrawal were (S)AEs identified by the investigator to cause participant withdrawal until the resolution of the event. These participant withdrawals were considered different from participant withdrawals for other reasons.
Time frame: From birth up to 180 days post-birth
Percentage of Infant Participants Reporting MAEs From Birth up to 180 Days Post-birth
An MAE was defined as an unsolicited AE for which the participants received medical attention such as hospitalization, or an emergency room visit, or visit to/by a health care provider.
Time frame: From birth up to 180 days post-birth
Percentage of Infant Participants Reporting Any SAEs From Birth up to 365 Days Post-birth
An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect or resulted in other situations that were considered serious per medical or scientific judgment. Any = occurrence of any SAE regardless of intensity grade or relation to vaccination.
Time frame: From birth up to 365 days post-birth
Number of Infant Participants Reporting (S)AEs Leading to Study Withdrawal From Birth up to 365 Days Post-birth
A participant was considered to have withdrawn from the study if no new study procedure had been performed or no new information had been collected for her since the date of withdrawal/last contact. (S)AEs leading to study withdrawal were (S)AEs identified by the investigator to cause participant withdrawal until the resolution of the event. These participant withdrawals were considered different from participant withdrawals for other reasons.
Time frame: From birth up to 365 days post-birth
Percentage of Infant Participants Reporting MAEs From Birth up to 365 Days Post-birth
An MAE was defined as an unsolicited AE for which the participants received medical attention such as hospitalization, or an emergency room visit, or visit to/by a health care provider.
Time frame: From birth up to 365 days post-birth
RSV MAT Immunoglobulin G (IgG)-Specific Antibody Concentrations for Maternal Participants at Pre-dosing (Day 1)
RSV MAT IgG-specific antibody concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and expressed as geometric mean concentrations (GMCs) in ELISA units per milliliter (ELU/mL).
Time frame: At pre-dosing (Day 1)
RSV MAT IgG-specific Antibody Concentrations for Maternal Participants at Delivery
RSV MAT IgG-specific antibody concentrations were determined by ELISA and expressed as GMCs in ELU/mL.
Time frame: At delivery
RSV-A Neutralizing Titers for Maternal Participants at Pre-dosing (Day 1)
RSV-A neutralizing titers were determined by neutralization assay and expressed as geometric mean titers (GMTs).
Time frame: At pre-dosing (Day 1)
RSV-A Neutralizing Titers for Maternal Participants at Delivery
RSV-A neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At delivery
Geometric Mean Ratio (GMR) Between Cord Blood and Maternal RSV MAT IgG-specific Antibody Concentrations
The placental transfer ratio of IgG-specific antibody concentration was determined from cord blood (or infant blood sample collected within 72 hours after birth \[if no cord blood could be obtained\]) over that of the blood sample from mother at delivery (if no blood sample was collected during delivery).
Time frame: At delivery (for maternal participants) or within 72 hours after birth (for infant participants)
RSV MAT IgG-specific Antibody Concentrations for Infant Participants at Delivery or Within 72 Hours After Birth
RSV MAT IgG-specific antibody concentrations were determined by ELISA and expressed as GMCs in ELU/mL. The antibody concentrations were measured on the cord blood sample collected at delivery, or on a blood sample collected from the infant within 72 hours after birth (if no cord blood sample could be obtained).
Time frame: At delivery or within 72 hours after birth
RSV-A Neutralizing Titers for Infant Participants at Delivery or Within 72 Hours After Birth
RSV-A neutralizing titers were determined by neutralization assay and expressed as GMTs. The titers were measured on the cord blood sample collected at delivery, or on a blood sample collected from the infant within 72 hours after birth (if no cord blood sample could be obtained).
Time frame: At delivery or within 72 hours after birth
Percentage of Maternal Participants Reporting Any SAEs From Day 1 up to 180 Days Post-delivery
An SAE was defined as any untoward medical occurrence that resulted in death, was life-threatening, required hospitalization or prolongation of existing hospitalization, resulted in disability/incapacity, was a congenital anomaly/birth defect in the offspring of a study participant or resulted in abnormal pregnancy outcomes or in other situations that were considered serious per medical or scientific judgment. Any = occurrence of any SAE regardless of intensity grade or relation to vaccination.
Time frame: From Day 1 up to 180 days post-delivery
Number of Maternal Participants Reporting (S)AEs Leading to Study Withdrawal From Day 1 up to 180 Days Post-delivery
A participant was considered to have withdrawn from the study if no new study procedure had been performed or no new information had been collected for her since the date of withdrawal/last contact. (S)AEs leading to study withdrawal were (S)AEs identified by the investigator to cause participant withdrawal until the resolution of the event. These participant withdrawals were considered different from participant withdrawals for other reasons.
Time frame: From Day 1 up to 180 days post-delivery
Percentage of Maternal Participants Reporting MAEs From Day 1 up to 180 Days Post-delivery
An MAE was defined as an unsolicited AE for which the participants received medical attention such as hospitalization, or an emergency room visit, or visit to/by a health care provider.
Time frame: From Day 1 up to 180 days post-delivery
Percentage of Maternal Participants Reporting Worsening of Pre-existing Medical Conditions and/or Obstetric Complications From Day 1 up to 180 Days Post-delivery
Worsening of pre-existing medical condition and/or obstetric complication was considered by the investigator, using clinical judgement and the following criteria: * Change in medication and/or medication dose. * Medically attended event in relation to pre-existing condition and/or obstetric complication that are outside the routine management of the condition/complication. * SAE and/or hospitalization in relation to pre-existing condition and/or obstetric complication.
Time frame: From Day 1 up to 180 days post-delivery
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GSK Investigational Site
Lafayette, Louisiana, United States
GSK Investigational Site
Slidell, Louisiana, United States
GSK Investigational Site
Missoula, Montana, United States
GSK Investigational Site
Arlington, Texas, United States
GSK Investigational Site
Austin, Texas, United States
...and 25 more locations
Number of Maternal Participants Reporting RSV-associated Medically Attended Respiratory Tract Illnesses (MA-RTIs) From Day 1 up to 180 Days Post-delivery
RSV-associated MA-RTI was defined as a medically attended visit for RTI symptoms and confirmed RSV infection.
Time frame: From Day 1 up to 180 days post-delivery
Percentage of Infant Participants Reporting Medically Assessed, RSV-associated Lower Respiratory Tract Illness (LRTIs) of Any Severity and RSV-associated Severe LRTIs From Birth up to 365 Days Post-birth
An RSV-associated LRTI is characterized by a history of cough OR difficulty in breathing, AND a blood oxygen saturation by pulse oximetry (SpO2) lower than (\<) 95%, OR respiratory rate increase AND a confirmed RSV infection. An RSV-associated severe LRTI meets the case definition of RSV-LRTI AND is additionally characterized by a SpO2 \<93%, OR lower chest wall in-drawing, OR inability to feed, OR failure to respond/unconscious.
Time frame: From birth up to 365 days post-birth
Percentage of Infant Participants Reporting Medically Assessed, RSV-associated Hospitalizations From Birth up to 365 Days Post-birth
RSV-associated hospitalization was defined as a confirmed RSV infection and hospitalized for acute medical condition. Hospitalization was defined as admission for observation or treatment based on the judgment of a health care provider.
Time frame: From birth up to 365 days post-birth
RSV MAT IgG-specific Antibody Concentrations for Maternal Participants at Day 31 Post-dosing
RSV MAT IgG-specific antibody concentrations were determined by ELISA and expressed as GMCs in ELU/mL.
Time frame: At Day 31 post-dosing
RSV-A Neutralizing Titers for Maternal Participants at Day 31 Post-dosing
RSV-A neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At Day 31 post-dosing
RSV-B Neutralizing Titers for Maternal Participants at Pre-dosing (Day 1), Day 31 Post-dosing and Delivery
RSV-B neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At pre-dosing (Day 1), Day 31 post-dosing and delivery
RSV-B Neutralizing Titers for Infant Participants at Delivery or Within 72 Hours After Birth
RSV-B neutralizing titers were determined by neutralization assay and expressed as GMTs. The titers were measured on the cord blood sample collected at delivery, or on a blood sample collected from the infant within 72 hours after birth (if no cord blood sample could be obtained).
Time frame: At delivery or within 72 hours after birth
RSV MAT IgG-specific Antibody Concentrations for Infant Participants at Day 43 Post-birth
RSV MAT IgG-specific antibody concentrations were determined by ELISA and expressed as GMCs in ELU/mL.
Time frame: At Day 43 post-birth
RSV MAT IgG-specific Antibody Concentrations for Infant Participants at Day 121 Post-birth
RSV MAT IgG-specific antibody concentrations were determined by ELISA and expressed as GMCs in ELU/mL.
Time frame: At Day 121 post-birth
RSV MAT IgG-specific Antibody Concentrations for Infant Participants at Day 181 Post-birth
RSV MAT IgG-specific antibody concentrations were determined by ELISA and expressed as GMCs in ELU/mL.
Time frame: At Day 181 post-birth
RSV-A Neutralizing Titers for Infant Participants at Day 43 Post-birth
RSV-A neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At Day 43 post-birth
RSV-A Neutralizing Titers for Infant Participants at Day 121 Post-birth
RSV-A neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At Day 121 post-birth
RSV-A Neutralizing Titers for Infant Participants at Day 181 Post-birth
RSV-A neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At Day 181 post-birth
RSV-B Neutralizing Titers for Infant Participants at Day 43 Post-birth
RSV-B neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At Day 43 post-birth
RSV-B Neutralizing Titers for Infant Participants at Day 121 Post-birth
RSV-B neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At Day 121 post-birth
RSV-B Neutralizing Titers for Infant Participants at Day 181 Post-birth
RSV-B neutralizing titers were determined by neutralization assay and expressed as GMTs.
Time frame: At Day 181 post-birth