A PHASE 2B, RANDOMIZED, PLACEBO-CONTROLLED, OBSERVER-BLINDED TRIAL TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF A RESPIRATORY SYNCYTIAL VIRUS (RSV) VACCINE IN PREGNANT WOMEN 18 THROUGH 49 YEARS OF AGE AND THEIR INFANTS

Percentage of Maternal Participants With Adverse Events (AEs) Within 1 Month After Vaccination

时间窗: Within 1 month after vaccination

An AE was any untoward medical occurrence in a participant who received investigational product without regard to possibility of causal relationship. AEs included both serious and non-serious adverse events. Serious adverse event (SAE) was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect.

Percentage of Infant Participants With Specific Birth Complications

时间窗: At birth

Specific birth complications included clavicle fracture, torticollis, cephalhematoma, premature baby, acute respiratory failure, meconium aspiration syndrome, neonatal pneumothorax, neonatal respiratory depression, neonatal respiratory distress, neonatal respiratory distress syndrome, neonatal respiratory failure, pneumothorax, respiratory distress, transient tachypnea of the newborn and subgaleal hemorrhage. Percentage of participants with any specific birth complications were reported in this outcome measure.

Percentage of Infant Participants With Any AE Within 1 Month of Age

时间窗: Within 1 month after birth

An AE was any untoward medical occurrence in a participant who received investigational product without regard to possibility of causal relationship. AEs included both serious and non-serious adverse events. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect.

Percentage of Infant Participants With AEs of Special Interest of at Least Moderate Severity Within 12 Months of Age: Congenital Anomalies and Developmental Delay

时间窗: Within 12 months after birth

AEs of special interest for infant participants included congenital anomalies and developmental delays. Congenital anomalies were defined as structural or functional anomalies that occurred during intrauterine life and could be identified prenatally, at birth or later in life. Severity was assessed based on the study investigator's judgement and graded as grade 1= mild (does not interfere with participant's usual function); grade 2= moderate (interferes to some extent with participant's usual function); grade 3= severe (interferes significantly with participant's usual function) and grade 4= life-threatening (life-threatening consequences; urgent intervention indicated). Percentage of infant participants with AEs of special interest of at least moderate severity were presented.

Percentage of Maternal Participants With Serious Adverse Events (SAEs), Medically Attended Adverse Events (MAEs) and Obstetric Complications

时间窗: From day of vaccination (Day 1) up to 12 months post-delivery

MAE was defined as a non-serious AE that results in an evaluation at a medical facility. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect. Obstetric complications were determined as per the study clinician's judgement.

Percentage of Maternal Participants With Prespecified Local Reactions by Maximum Severity Within 7 Days After Vaccination

时间窗: Within 7 days after vaccination

Local reactions included pain at injection site, redness and swelling and were recorded by participants in an electronic diary (e-diary). Redness and swelling were measured and recorded in measuring device units. 1 measuring device unit =0.5 centimeter (cm) and graded as mild: greater than (\>) 2.0 to 5.0 cm, moderate: \>5.0 to 10.0 cm and severe: \>10.0 cm. Pain at injection site was graded as mild: did not interfere with daily activity, moderate: interfered with daily activity and severe: prevented daily activity. The maximum severity was defined as highest grading of each local reaction within 7 days of vaccination.

Percentage of Maternal Participants With Prespecified Systemic Events by Maximum Severity Within 7 Days After Vaccination

时间窗: Within 7 days after vaccination

Systemic events included fever, fatigue, headache, nausea, muscle pain, joint pain, vomiting, diarrhea and were recorded by participants in an e-diary. Fever was categorized as: grade 1: mild (\>=38.0 to 38.4 degrees \[deg\] Celsius \[C\]), grade 2: moderate (\>38.4 to 38.9 deg C), grade 3: severe (\>38.9 to 40.0 deg C) and grade 4 (\>40.0 deg C). Fatigue, headache, nausea, muscle pain and joint pain were graded as mild: did not interfere with activity, moderate: some interference with activity and severe: prevented daily routine activity. Vomiting was graded as mild: 1 to 2 times in 24 hours(h), moderate: \>2 times in 24h and severe: required intravenous hydration. Diarrhea was graded as mild: 2 to 3 loose stools in 24h, moderate: 4 to 5 loose stools in 24h and severe: 6 or more loose stools in 24h. The maximum severity was defined as highest grading of each systemic event within 7 days of vaccination.

Percentage of Infant Participants With MAEs and SAEs Within 12 Months of Age

时间窗: Within 12 months after birth

MAE was defined as a non-serious AE that results in an evaluation at a medical facility. SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly/birth defect.