Percentage of participants achieving Anti-TTd antibody concentrations of \>= 0.1 IU/mL at 1 month after vaccination were reported. The lower limit of quantitation (LLOQ) values for Anti-TTd was 0.05 IU/mL. Assay results below the LLOQ were set to 0.5\*LLOQ. Data for this outcome measure was planned to be collected and analyzed only for combined population of participants reported under two RSV vaccine arms: (RSV vaccine 120 mcg with Tdap and RSV vaccine 240 mcg with aluminum hydroxide/Tdap) along with placebo/Tdap arm and not planned to be collected and analyzed for two RSV vaccine arms: (RSV vaccine 120 mcg with placebo and RSV vaccine 240 mcg with aluminum hydroxide with placebo), as pre-specified in protocol.

Percentage of participants achieving Anti-DTd antibody concentrations of \>= 0.1 IU/mL at 1 month after vaccination were reported. The LLOQ values for Anti- DTd= 0.037 IU/mL. Assay results below the LLOQ were set to 0.5\*LLOQ. Data for this outcome measure was planned to be collected and analyzed only for combined population of participants reported under two RSV vaccine arms: (RSV vaccine 120 mcg with Tdap and RSV vaccine 240 mcg with aluminum hydroxide/Tdap) along with placebo/Tdap arm and not planned to be collected and analyzed for two RSV vaccine arms: (RSV vaccine 120 mcg with placebo and RSV vaccine 240 mcg with aluminum hydroxide with placebo), as pre-specified in protocol.

GMCs of anti-pertussis components: anti pertussis (anti-PT) toxin, anti filamentous hemagglutinin (FHA) and anti- pertactin (PRN) was measured and reported in descriptive section. LLOQ values for each component was: Anti-PT=0.9 endotoxin units per milliliter (EU/mL), Anti-FHA=2.9 EU/mL, and Anti-PRN=3.0 EU/mL. Assay results below LLOQ were set to 0.5\*LLOQ. Descriptive data for this outcome measure was planned to be collected and analyzed only for combined population of participants reported under two RSV vaccine arms: (RSV vaccine 120 mcg with Tdap and RSV vaccine 240 mcg with aluminum hydroxide/Tdap) along with placebo/Tdap arm and not planned to be collected and analyzed for two RSV vaccine arms: (RSV vaccine 120 mcg with placebo and RSV vaccine 240 mcg with aluminum hydroxide with placebo), as pre-specified in protocol. GMRs were reported in statistical analysis section and calculated by dividing GMC of RSV vaccine with aluminum hydroxide with Tdap arm by GMC of placebo/Tdap arm.

Assay results below the LLOQ were set to 0.5\*LLOQ. Titers were expressed in terms of 1/dilution. Descriptive data for this outcome measure was planned to be collected and analyzed for combined population of participants reported under two RSV and Tdap vaccine arms: (RSV vaccine 120 mcg with Tdap and RSV vaccine 240 mcg with aluminum hydroxide/Tdap) and two RSV and placebo arm: (RSV vaccine 120 mcg with placebo and RSV vaccine 240 mcg with aluminum hydroxide with placebo) and not planned to be collected and analyzed for Placebo/Tdap arm, as pre-specified in protocol. GMRs were reported in statistical analysis section and calculated by dividing GMT of RSV vaccine with aluminum hydroxide with Tdap arm by GMT of RSV vaccine with aluminum hydroxide with placebo arm.

Assay results below the LLOQ were set to 0.5\*LLOQ. Titers were expressed in terms of 1/dilution. Descriptive data for this outcome measure was planned to be collected and analyzed for combined population of participants reported under two RSV and Tdap vaccine arms: (RSV vaccine 120 mcg with Tdap and RSV vaccine 240 mcg with aluminum hydroxide/Tdap) and two RSV and placebo arm: (RSV vaccine 120 mcg with placebo and RSV vaccine 240 mcg with aluminum hydroxide with placebo) and not planned to be collected and analyzed for Placebo/Tdap arm, as pre-specified in protocol. GMRs were reported in statistical analysis section and calculated by dividing GMT of RSV vaccine with aluminum hydroxide with Tdap arm by GMT of RSV vaccine with aluminum hydroxide with placebo arm.

Local reactions included pain at injection site, redness and swelling 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.

Systemic reactions included fever, fatigue/tiredness, headache, nausea, muscle pain, joint pain, vomiting, diarrhea and any systemic event recorded by participants in an e-diary. Fever was categorized as: \>=38.0 degrees (deg) Celsius (C), mild (\>=38.0 to 38.4 deg C, \>38.4 to 38.9 deg C), moderate (\>38.9 to 40.0 deg C and \>40.0 deg C), severe (\>38.9 deg C 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: requires 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.

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.

An medically attended adverse events (MAE) was defined as a non-serious AE that results in an evaluation at a medical facility. 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.

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.

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.

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.

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.

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.

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.

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.

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.