Trial Outcomes & Findings for A Study to Determine the Safety and Efficacy of the RSV F Vaccine to Protect Infants Via Maternal Immunization (NCT NCT02624947)

Last Updated: 2025-05-06

Results Overview

Percentages of infants with medically-significant RSV LRTI from delivery through 90, 120,150, and 180 days of life, as defined by: * The presence of RSV infection confirmed by detection of RSV genome by RT-PCR on respiratory secretions (obtained within the continuous illness episode which fulfills the other criteria listed below); AND * At least one manifestation of lower respiratory tract infection (LRTI) from among the following: cough, nasal flaring, lower chest wall indrawing, subcostal retractions, stridor, rales, rhonchi, wheezing, crackles/crepitations, or observed apnea; AND * Evidence of medical significance as defined by the presence of: * EITHER hypoxemia (peripheral oxygen saturation \[SpO2\] \< 95% at sea level or \< 92% at altitudes \> 1800 meters) OR * Tachypnea (≥ 70 breaths per minute \[bpm\] in infants 0 to 59 days of age and ≥ 60 bpm in infants ≥ 60 days of age).

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

4636 participants

Primary outcome timeframe

Delivery to 180 days after delivery

Results posted on

2025-05-06

Participant Flow

Participants took part in a study at 86 sites in 11 different countries from 03 December 2015 to 12 July 2019.

Healthy women 18-40 years of age with low-risk singleton pregnancies enrolled and treated in the study with 120 µg Respiratory Syncytial Virus Recombinant F (RSVF) nanoparticle vaccine adsorbed to 0.4 mg of Aluminum (as phosphate salt) ) or formulated buffer (placebo control) as a single 0.5 mL IM (Intramuscular) injection into the deltoid muscle.

Participant milestones

Participant milestones
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) Maternal participants were administered with the adjuvanted RSV F vaccine 120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum (as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal Participants STARTED	3051	1585
Maternal Participants Participants in Safety Population	3045	1581
Maternal Participants COMPLETED	2907	1510
Maternal Participants NOT COMPLETED	144	75
Infant Participants STARTED	3014	1565
Infant Participants Participants in Safety Population	3008	1561
Infant Participants All Live Births	3014	1565
Infant Participants COMPLETED	2783	1433
Infant Participants NOT COMPLETED	231	132

Reasons for withdrawal

Reasons for withdrawal
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) Maternal participants were administered with the adjuvanted RSV F vaccine 120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum (as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal Participants Adverse Event	5	0
Maternal Participants Investigator Decision	5	3
Maternal Participants Lost to Follow-up	54	24
Maternal Participants Non Compliance	8	5
Maternal Participants Sponsor Request	1	1
Maternal Participants Voluntary withdrawal unrelated to AE	48	27
Maternal Participants Miscellaneous	23	15
Infant Participants Adverse Event	18	11
Infant Participants Investigator Decision	5	4
Infant Participants Lost to Follow-up	93	58
Infant Participants Non Compliance	17	7
Infant Participants Sponsor Request	0	1
Infant Participants Voluntary Withdrawal unrelated to AE	48	25
Infant Participants Miscellaneous	50	26

Baseline Characteristics

Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered the adjuvant RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle. Infants were monitored and data was collected based on the intervention given to the mothers.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle. Infants were monitored and data was collected based on the intervention given to the mothers.	Total n=4626 Participants Total of all reporting groups
Age, Continuous	26 years STANDARD_DEVIATION 5.3 • n=3045 Participants	26 years STANDARD_DEVIATION 5.2 • n=1581 Participants	26 years STANDARD_DEVIATION 5.3 • n=4626 Participants
Age, Customized Gestational Age at delivery (Infant Population)	39.3 weeks STANDARD_DEVIATION 1.49 • n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	39.3 weeks STANDARD_DEVIATION 1.58 • n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	39.3 weeks STANDARD_DEVIATION 1.52 • n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Sex/Gender, Customized Female	1449 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	757 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	2206 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Sex/Gender, Customized Male	1556 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	799 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	2355 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Sex/Gender, Customized No data	3 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	5 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	8 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Ethnicity (NIH/OMB) Hispanic or Latino	409 Participants n=3045 Participants	212 Participants n=1581 Participants	621 Participants n=4626 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	2636 Participants n=3045 Participants	1369 Participants n=1581 Participants	4005 Participants n=4626 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=3045 Participants	0 Participants n=1581 Participants	0 Participants n=4626 Participants
Race (NIH/OMB) American Indian or Alaska Native	22 Participants n=3045 Participants	11 Participants n=1581 Participants	33 Participants n=4626 Participants
Race (NIH/OMB) Asian	320 Participants n=3045 Participants	168 Participants n=1581 Participants	488 Participants n=4626 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	49 Participants n=3045 Participants	27 Participants n=1581 Participants	76 Participants n=4626 Participants
Race (NIH/OMB) Black or African American	1335 Participants n=3045 Participants	682 Participants n=1581 Participants	2017 Participants n=4626 Participants
Race (NIH/OMB) White	903 Participants n=3045 Participants	489 Participants n=1581 Participants	1392 Participants n=4626 Participants
Race (NIH/OMB) More than one race	416 Participants n=3045 Participants	204 Participants n=1581 Participants	620 Participants n=4626 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=3045 Participants	0 Participants n=1581 Participants	0 Participants n=4626 Participants
Race/Ethnicity, Customized White or Caucasian	900 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	477 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	1377 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized Black or African American	1387 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	696 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	2083 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized Asian	310 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	162 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	472 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized American Indian or Alaska Native	21 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	9 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	30 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized Native Hawaiian or other Pacific Islander	55 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	28 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	83 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized Other	333 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	187 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	520 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized No data	2 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	2 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	4 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized Hispanic or Latino	403 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	213 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	616 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized Not Hispanic or Latino	2603 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	1346 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	3949 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.
Race/Ethnicity, Customized Na data	2 Participants n=3008 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	2 Participants n=1561 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.	4 Participants n=4569 Participants • Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.

PRIMARY outcome

Timeframe: Delivery to 180 days after delivery

Population: Analysis population includes infant participants who were ≥ 37 weeks GA at birth, and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=2765 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1430 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Percentages of Participants With Medically Significant RSV LRTI With Either Hypoxemia (SpO2 <95% at Sea Level or <92% at Altitudes >1800 Meters) or Tachypnea Day 90	41 Participants	35 Participants
Infants: Percentages of Participants With Medically Significant RSV LRTI With Either Hypoxemia (SpO2 <95% at Sea Level or <92% at Altitudes >1800 Meters) or Tachypnea Day 120	52 Participants	41 Participants
Infants: Percentages of Participants With Medically Significant RSV LRTI With Either Hypoxemia (SpO2 <95% at Sea Level or <92% at Altitudes >1800 Meters) or Tachypnea Day 150	57 Participants	43 Participants
Infants: Percentages of Participants With Medically Significant RSV LRTI With Either Hypoxemia (SpO2 <95% at Sea Level or <92% at Altitudes >1800 Meters) or Tachypnea Day 180	61 Participants	43 Participants

SECONDARY outcome

Timeframe: Delivery to 180 days after delivery

The number of infants with RSV LRTI with EITHER severe hypoxemia (SpO2 \< 92% at sea level or \< 87% at altitudes \> 1800 meters) OR the documented use of oxygen by high flow nasal cannula OR CPAP OR BiPAP OR Bubble CPAP OR bag-mask ventilation OR intubation with subsequent mechanical (or manual) ventilation OR ECMO from delivery through 90, 120, 150, and 180 days of life.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=2765 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1430 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Number of Participants With RSV LRTI With Severe Hypoxemia (Sp02 <92% at Sea Level or <87% at Altitudes >1800 Meters) or Documented Use of Oxygen by High Flow Nasal Cannula or Other Advanced Respiratory Support Through 90 Days of Life Day 180	19 Participants	17 Participants
Infants: Number of Participants With RSV LRTI With Severe Hypoxemia (Sp02 <92% at Sea Level or <87% at Altitudes >1800 Meters) or Documented Use of Oxygen by High Flow Nasal Cannula or Other Advanced Respiratory Support Through 90 Days of Life Day 90	14 Participants	14 Participants
Infants: Number of Participants With RSV LRTI With Severe Hypoxemia (Sp02 <92% at Sea Level or <87% at Altitudes >1800 Meters) or Documented Use of Oxygen by High Flow Nasal Cannula or Other Advanced Respiratory Support Through 90 Days of Life Day 120	16 Participants	16 Participants
Infants: Number of Participants With RSV LRTI With Severe Hypoxemia (Sp02 <92% at Sea Level or <87% at Altitudes >1800 Meters) or Documented Use of Oxygen by High Flow Nasal Cannula or Other Advanced Respiratory Support Through 90 Days of Life Day 150	17 Participants	17 Participants

SECONDARY outcome

Timeframe: Delivery to 180 days after delivery

Population: The analysis population includes infant participants who were ≥ 37 weeks GA at birth and born to maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery, and had not received prophylactic treatment with palivizumab between birth and Day 180 after delivery, and had at least 1 documented post-partum contact during which active and/or passive surveillance activities for RSV-suspect illness could occur.

Percentages of infants with RSV LRTI with hospitalization from delivery through 90, 120, 150, and 180 days of life.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=2765 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1430 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Percentages of Participants With RSV LRTI With Hospitalization From Delivery Day 90	57 Participants	53 Participants
Infants: Percentages of Participants With RSV LRTI With Hospitalization From Delivery Day 120	64 Participants	56 Participants
Infants: Percentages of Participants With RSV LRTI With Hospitalization From Delivery Day 150	67 Participants	57 Participants
Infants: Percentages of Participants With RSV LRTI With Hospitalization From Delivery Day 180	68 Participants	59 Participants

SECONDARY outcome

Timeframe: Delivery to 364 days after delivery

Population: The analysis population includes all infants born live to maternal subjects who received any test article and was analyzed as randomized unless conclusive documentation existed to confirm the mis-dosing of their respective mother and the identity of the treatment actually received.

Number of infants with AEs and SAEs (with special attention to congenital anomalies; respiratory failure other than RSV-associated hospitalization; neonatal death; infant death; sudden infant death syndrome; asphyxia; neonatal or hypoxic-ischemic encephalopathy; or other adverse events or complications of adverse events that necessitate hospitalization) during the neonatal period and through the first year of life.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infant: Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) During the Neonatal Period and Through the First Year of Life Pre-Specified AESIs	275 participants	151 participants
Infant: Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) During the Neonatal Period and Through the First Year of Life Any AEs	2468 participants	1295 participants
Infant: Number of Participants With Adverse Events (AEs) and Serious Adverse Events (SAEs) During the Neonatal Period and Through the First Year of Life Overall SAEs (Including AESIs)	1337 participants	724 participants

SECONDARY outcome

Timeframe: Day 180 after delivery

Number of infants with potential developmental delay (a term used to describe a delay in a child's development), as measured by the outcome of testing with the Ages and Stages Questionnaire-3 at 6 months and at 1 year, in infants of RSV F vaccinees as compared to placebo.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Number of Participants With Potential Developmental Delay With any 6 months ASQ data	2835 participants	1460 participants
Infants: Number of Participants With Potential Developmental Delay On schedule for communication	2773 participants	1424 participants
Infants: Number of Participants With Potential Developmental Delay On schedule for Gross Motor	2588 participants	1298 participants
Infants: Number of Participants With Potential Developmental Delay On schedule for Fine Motor	2603 participants	1364 participants
Infants: Number of Participants With Potential Developmental Delay On schedule for Problem Solving	2648 participants	1381 participants
Infants: Number of Participants With Potential Developmental Delay On Schedule for Personal-Social	2481 participants	1280 participants

SECONDARY outcome

Timeframe: Day 0 to Day 7

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

A number of maternal participants with solicited injection site and systemic reactogenicity within seven days of vaccination.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Number of Participants With Solicited Injection Site and Systemic Reactogenicity Total Solicited Local AE's	1240 participants	157 participants
Maternal: Number of Participants With Solicited Injection Site and Systemic Reactogenicity Total Solicited Systematic AE's	1255 participants	611 participants

SECONDARY outcome

Timeframe: Delivery to 180 days after delivery

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Number of maternal participants with unsolicited (local and systemic) adverse events (AEs), unscheduled medically-attended adverse events (MAEs), significant new medical conditions (SNMCs), and serious adverse events (SAEs) through delivery and six (6) months thereafter.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Number of Participants With Unsolicited Adverse Events, Medically-attended Adverse Events (MAEs), Significant New Medical Conditions (SNMCs) and Serious Adverse Events (SAEs) Unsolicited AEs	2004 participants	1022 participants
Maternal: Number of Participants With Unsolicited Adverse Events, Medically-attended Adverse Events (MAEs), Significant New Medical Conditions (SNMCs) and Serious Adverse Events (SAEs) SNMCs	65 participants	38 participants
Maternal: Number of Participants With Unsolicited Adverse Events, Medically-attended Adverse Events (MAEs), Significant New Medical Conditions (SNMCs) and Serious Adverse Events (SAEs) SAEs	906 participants	455 participants
Maternal: Number of Participants With Unsolicited Adverse Events, Medically-attended Adverse Events (MAEs), Significant New Medical Conditions (SNMCs) and Serious Adverse Events (SAEs) MAEs	1534 participants	802 participants

SECONDARY outcome

Timeframe: Delivery

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Number of maternal subjects that had either Caesarean, vaginal, or instrument-assisted vaginal modes of delivery.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery Unknown	16 count of participants	10 count of participants
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery No Data	22 count of participants	16 count of participants
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery Vaginal (spontaneous)	2110 count of participants	1076 count of participants
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery Forceps or vacuum assisted delivery	91 count of participants	56 count of participants
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery Planned (repeat) Caesarean delivery	225 count of participants	132 count of participants
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery Planned (primary) Caesarean delivery	111 count of participants	47 count of participants
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery Caesarean delivery after failed attempt at vaginal delivery	123 count of participants	66 count of participants
Maternal: Number of Participants With Caesarean, Vaginal, or Instrument Assisted Vaginal Modes of Delivery Emergency Caesarean delivery	347 count of participants	178 count of participants

SECONDARY outcome

Timeframe: Day 14 to Delivery

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG, PCA, and RSV Types A and B - MN assays) among Maternal Participants from Day 14 until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=2775 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1445 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Delivery (MN - RSV/A)	2.20 Fold Ratio Interval 2.1 to 2.3	0.89 Fold Ratio Interval 0.86 to 0.93
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Day 14 (MN - RSV/B)	3.00 Fold Ratio Interval 2.56 to 3.51	0.96 Fold Ratio Interval 0.88 to 1.04
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Delivery (MN - RSV/B)	2.15 Fold Ratio Interval 2.06 to 2.25	0.88 Fold Ratio Interval 0.84 to 0.93
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Day 14 (Anti F-IgG)	18.59 Fold Ratio Interval 17.85 to 19.37	0.99 Fold Ratio Interval 0.97 to 1.02
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Delivery (Anti F-IgG)	14.37 Fold Ratio Interval 13.86 to 14.9	0.92 Fold Ratio Interval 0.9 to 0.95
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Day 14 (PCA)	12.38 Fold Ratio Interval 11.97 to 12.81	0.94 Fold Ratio Interval 0.92 to 0.96
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Delivery (PCA)	9.94 Fold Ratio Interval 9.64 to 10.25	0.92 Fold Ratio Interval 0.9 to 0.94
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMFR Day 14 (MN - RSV/A)	2.35 Fold Ratio Interval 2.06 to 2.68	0.98 Fold Ratio Interval 0.92 to 1.05

SECONDARY outcome

Timeframe: Day 14 to Delivery

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG, PCA, and RSV Types A and B - MN assays) among Maternal Participants from Day 14 until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (PCA)	99.4 percentage of participants Interval 99.0 to 99.7	5.0 percentage of participants Interval 3.9 to 6.3
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (PCA)	97.9 percentage of participants Interval 97.3 to 98.4	4.2 percentage of participants Interval 3.2 to 5.4
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (MN - RSV/A)	71.3 percentage of participants Interval 61.0 to 80.1	4.3 percentage of participants Interval 1.2 to 10.8
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (MN - RSV/B)	70.2 percentage of participants Interval 59.9 to 79.2	8.7 percentage of participants Interval 3.8 to 16.4
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (Anti F-IgG)	98.3 percentage of participants Interval 97.7 to 98.7	5.0 percentage of participants Interval 3.9 to 6.3
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (Anti F-IgG)	97.5 percentage of participants Interval 96.8 to 98.0	5.0 percentage of participants Interval 3.9 to 6.2
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (MN - RSV/A)	55.6 percentage of participants Interval 52.3 to 59.0	4.9 percentage of participants Interval 3.2 to 7.2
Maternal: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (MN - RSV/B)	57.2 percentage of participants Interval 53.8 to 60.5	4.9 percentage of participants Interval 3.2 to 7.2

SECONDARY outcome

Timeframe: Day 14 to Delivery

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG, PCA, and RSV Types A and B - MN assays) among Maternal Participants from Day 14 until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (MN - RSV/B)	70.2 percentage of participants Interval 59.9 to 79.2	8.7 percentage of participants Interval 3.8 to 16.4
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery (MN - RSV/A)	59.0 percentage of participants Interval 55.6 to 62.2	5.5 percentage of participants Interval 3.7 to 7.9
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery(Anti F-IgG)	98.1 percentage of participants Interval 97.5 to 98.5	2.2 percentage of participants Interval 1.5 to 3.1
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (PCA)	98.0 percentage of participants Interval 97.3 to 98.5	0.5 percentage of participants Interval 0.2 to 1.1
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery (PCA)	97.7 percentage of participants Interval 97.1 to 98.3	2.1 percentage of participants Interval 1.4 to 3.0
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (MN - RSV/A)	69.1 percentage of participants Interval 58.8 to 78.3	4.3 percentage of participants Interval 1.2 to 10.8
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (Anti F-IgG)	98.3 percentage of participants Interval 97.8 to 98.8	1.1 percentage of participants Interval 0.6 to 1.8
Maternal: Percentage of Participants Who Seroconverted (2 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery (MN - RSV/B)	53.2 percentage of participants Interval 49.8 to 56.5	4.3 percentage of participants Interval 2.7 to 6.5

SECONDARY outcome

Timeframe: Day 14 to Delivery

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG, PCA, and RSV Types A and B - MN assays) among Maternal Participants from Day 14 until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (Anti F-IgG)	91.8 percentage of participants Interval 90.7 to 92.8	0.4 percentage of participants Interval 0.2 to 1.0
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery(Anti F-IgG)	89.7 percentage of participants Interval 88.5 to 90.8	0.9 percentage of participants Interval 0.5 to 1.5
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (PCA)	88.1 percentage of participants Interval 86.8 to 89.3	0.2 percentage of participants Interval 0.0 to 0.6
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery (PCA)	84.8 percentage of participants Interval 83.4 to 86.1	0.6 percentage of participants Interval 0.3 to 1.2
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (MN - RSV/A)	19.1 percentage of participants Interval 11.8 to 28.6	0 percentage of participants Interval 0.0 to 3.9
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery (MN - RSV/A)	18.6 percentage of participants Interval 16.1 to 21.3	1.2 percentage of participants Interval 0.5 to 2.7
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Day 14 (MN - RSV/B)	35.1 percentage of participants Interval 25.5 to 45.6	1.1 percentage of participants Interval 0.0 to 5.9
Maternal: Percentage of Participants Who Seroconverted (4 Fold Increase) as Determined by Immunogenicity of RSV F Vaccine and Placebo Delivery (MN - RSV/B)	17.6 percentage of participants Interval 15.1 to 20.3	1.0 percentage of participants Interval 0.3 to 2.4

SECONDARY outcome

Timeframe: Delivery to Day 180

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG, PCA, and RSV Types A and B - MN assays) among Infant Participants from Delivery until Day 180

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 60 (Anti-F IgG)	2355 percentage of participants Interval 2230.0 to 2487.0	242 percentage of participants Interval 231.0 to 254.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 90 (Anti-F IgG)	1298 percentage of participants Interval 1220.0 to 1382.0	216 percentage of participants Interval 209.0 to 224.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Delivery (Anti-F IgG)	9501 percentage of participants Interval 9224.0 to 9787.0	752 percentage of participants Interval 719.0 to 786.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 14 (Anti-F IgG)	6465 percentage of participants Interval 6134.0 to 6815.0	543 percentage of participants Interval 502.0 to 588.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 35 (Anti-F IgG)	3883 percentage of participants Interval 3683.0 to 4094.0	324 percentage of participants Interval 304.0 to 346.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 112/120 (Anti-F IgG)	690 percentage of participants Interval 645.0 to 737.0	218 percentage of participants Interval 209.0 to 227.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 180 (Anti-F IgG)	289 percentage of participants Interval 273.0 to 305.0	218 percentage of participants Interval 209.0 to 227.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Delivery (PCA)	136 percentage of participants Interval 132.0 to 139.0	15 percentage of participants Interval 14.0 to 15.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 14 (PCA)	103 percentage of participants Interval 98.0 to 107.0	12 percentage of participants Interval 11.0 to 12.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 35 (PCA)	69 percentage of participants Interval 66.0 to 72.0	8 percentage of participants Interval 8.0 to 8.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 60 (PCA)	45 percentage of participants Interval 43.0 to 48.0	7 percentage of participants Interval 6.0 to 7.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 90 (PCA)	29 percentage of participants Interval 27.0 to 30.0	6 percentage of participants Interval 6.0 to 7.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 112/120 (PCA)	17 percentage of participants Interval 16.0 to 18.0	6 percentage of participants Interval 6.0 to 7.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 180 (PCA)	8 percentage of participants Interval 8.0 to 9.0	6 percentage of participants Interval 6.0 to 7.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Delivery (MN - RSV/A)	1705 percentage of participants Interval 1602.0 to 1813.0	732 percentage of participants Interval 674.0 to 796.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 14 (MN - RSV/A)	1108 percentage of participants Interval 983.0 to 1250.0	505 percentage of participants Interval 427.0 to 596.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 35 (MN - RSV/A)	609 percentage of participants Interval 546.0 to 679.0	266 percentage of participants Interval 233.0 to 304.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 60 (MN - RSV/A)	370 percentage of participants Interval 330.0 to 415.0	190 percentage of participants Interval 164.0 to 222.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 90 (MN - RSV/A)	201 percentage of participants Interval 178.0 to 228.0	109 percentage of participants Interval 92.0 to 130.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 112/120 (MN - RSV/A)	110 percentage of participants Interval 96.0 to 127.0	61 percentage of participants Interval 51.0 to 73.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 180 (MN - RSV/A)	41 percentage of participants Interval 35.0 to 49.0	26 percentage of participants Interval 20.0 to 35.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Delivery (MN - RSV/B)	1292 percentage of participants Interval 1198.0 to 1393.0	607 percentage of participants Interval 544.0 to 678.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 14 (MN - RSV/B)	1079 percentage of participants Interval 642.0 to 1813.0	324 percentage of participants Interval 201.0 to 521.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 35 (MN - RSV/B)	422 percentage of participants Interval 243.0 to 732.0	195 percentage of participants Interval 134.0 to 248.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 60 (MN - RSV/B)	216 percentage of participants Interval 151.0 to 309.0	151 percentage of participants Interval 82.0 to 279.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 90 (MN - RSV/B)	185 percentage of participants Interval 113.0 to 301.0	61 percentage of participants Interval 34.0 to 111.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 112/120 (MN - RSV/B)	71 percentage of participants Interval 39.0 to 131.0	48 percentage of participants Interval 31.0 to 73.0
Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT Day 180 (MN - RSV/B)	34 percentage of participants Interval 17.0 to 65.0	24 percentage of participants Interval 9.0 to 67.0

SECONDARY outcome

Timeframe: Delivery to Day 180

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG, PCA, and RSV Types A and B - MN assays) among Infant Participants from Delivery until Day 180

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 90 (MN - RSV/B)	40.0 percentage of participants Interval 21.1 to 61.3	4.2 percentage of participants Interval 0.1 to 21.1
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 112/120 (MN - RSV/B)	5.3 percentage of participants Interval 0.1 to 26.0	3.7 percentage of participants Interval 0.1 to 19.0
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 180 (MN - RSV/B)	4.5 percentage of participants Interval 0.1 to 22.8	4.3 percentage of participants Interval 0.1 to 21.9
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (MN - RSV/A)	20.2 percentage of participants Interval 17.4 to 23.2	5.0 percentage of participants Interval 3.1 to 7.5
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (MN - RSV/A)	14.2 percentage of participants Interval 9.7 to 19.9	3.1 percentage of participants Interval 0.6 to 8.7
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (MN - RSV/B)	54.2 percentage of participants Interval 32.8 to 74.4	4.5 percentage of participants Interval 0.1 to 22.8
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (Anti-F IgG)	95.9 percentage of participants Interval 95.1 to 96.7	5.0 percentage of participants Interval 3.9 to 6.3
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (Anti-F IgG)	95.9 percentage of participants Interval 94.3 to 97.2	4.9 percentage of participants Interval 3.0 to 7.5
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 35 (Anti-F IgG)	94.1 percentage of participants Interval 92.3 to 95.7	4.8 percentage of participants Interval 3.0 to 7.2
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 60 (Anti-F IgG)	94.2 percentage of participants Interval 92.3 to 95.8	4.9 percentage of participants Interval 3.0 to 7.4
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 90 (Anti-F IgG)	77.0 percentage of participants Interval 74.0 to 79.9	4.9 percentage of participants Interval 3.0 to 7.4
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 112/120 (Anti-F IgG)	36.4 percentage of participants Interval 33.0 to 39.9	4.9 percentage of participants Interval 3.0 to 7.5
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 180 (Anti-F IgG)	6.5 percentage of participants Interval 4.9 to 8.5	4.9 percentage of participants Interval 3.0 to 7.5
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (PCA)	96.8 percentage of participants Interval 96.0 to 97.4	4.6 percentage of participants Interval 3.5 to 5.8
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 14 (PCA)	95.4 percentage of participants Interval 93.7 to 96.8	4.7 percentage of participants Interval 2.9 to 7.3
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 35 (PCA)	95.6 percentage of participants Interval 93.9 to 96.9	4.4 percentage of participants Interval 2.7 to 6.8
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 60 (PCA)	92.0 percentage of participants Interval 89.9 to 93.9	4.4 percentage of participants Interval 2.7 to 6.9
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 90 (PCA)	73.1 percentage of participants Interval 69.9 to 76.2	4.7 percentage of participants Interval 2.8 to 7.2
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 112/120 (PCA)	29.7 percentage of participants Interval 26.4 to 33.1	4.7 percentage of participants Interval 2.8 to 7.2
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 180 (PCA)	5.2 percentage of participants Interval 3.8 to 7.1	4.1 percentage of participants Interval 2.4 to 6.6
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 35 (MN - RSV/A)	19.5 percentage of participants Interval 14.5 to 25.5	3.6 percentage of participants Interval 1.2 to 8.3
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 60 (MN - RSV/A)	17.4 percentage of participants Interval 12.7 to 22.9	4.8 percentage of participants Interval 1.8 to 10.2
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 90 (MN - RSV/A)	13.8 percentage of participants Interval 9.6 to 19.0	4.8 percentage of participants Interval 1.8 to 10.2
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 112/120 (MN - RSV/A)	8.6 percentage of participants Interval 5.3 to 13.1	5.0 percentage of participants Interval 2.0 to 10.0
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 180 (MN - RSV/A)	3.5 percentage of participants Interval 1.5 to 6.8	4.2 percentage of participants Interval 1.4 to 9.6
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Delivery (MN - RSV/B)	11.2 percentage of participants Interval 9.1 to 13.7	4.3 percentage of participants Interval 2.5 to 6.6
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 35 (MN - RSV/B)	27.3 percentage of participants Interval 10.7 to 50.2	4.2 percentage of participants Interval 0.1 to 21.1
Infants: Percentage of Participants With a Seroresponse to RSV F Vaccine and Placebo Day 60 (MN - RSV/B)	5.0 percentage of participants Interval 0.1 to 24.9	4.2 percentage of participants Interval 0.1 to 21.1

SECONDARY outcome

Timeframe: Day 14 to Day 180

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG, PCA, and RSV Types A and B - MN assays) among Infant Participants from Day 14 until Day 180

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 35 (Anti-F IgG)	0.42 Fold Ratio Interval 0.41 to 0.43	0.44 Fold Ratio Interval 0.42 to 0.47
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 60 (Anti-F IgG)	0.24 Fold Ratio Interval 0.24 to 0.25	0.35 Fold Ratio Interval 0.33 to 0.35
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 90 (Anti-F IgG)	0.13 Fold Ratio Interval 0.13 to 0.14	0.30 Fold Ratio Interval 0.28 to 0.33
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 112/120 (Anti-F IgG)	0.07 Fold Ratio Interval 0.07 to 0.08	0.33 Fold Ratio Interval 0.29 to 0.36
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 180 (Anti-F IgG)	0.03 Fold Ratio Interval 0.03 to 0.03	0.32 Fold Ratio Interval 0.29 to 0.36
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 14 (PCA)	0.76 Fold Ratio Interval 0.73 to 0.78	0.76 Fold Ratio Interval 0.74 to 0.79
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 35 (PCA)	0.51 Fold Ratio Interval 0.49 to 0.52	0.58 Fold Ratio Interval 0.55 to 0.6
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 60 (PCA)	0.34 Fold Ratio Interval 0.33 to 0.35	0.49 Fold Ratio Interval 0.46 to 0.53
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 90 (PCA)	0.21 Fold Ratio Interval 0.2 to 0.22	0.46 Fold Ratio Interval 0.42 to 0.49
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 112/120 (PCA)	0.12 Fold Ratio Interval 0.12 to 0.13	0.51 Fold Ratio Interval 0.47 to 0.56
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 180 (PCA)	0.06 Fold Ratio Interval 0.06 to 0.06	0.50 Fold Ratio Interval 0.46 to 0.54
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 14 (MN - RSV/A)	0.68 Fold Ratio Interval 0.64 to 0.72	0.69 Fold Ratio Interval 0.63 to 0.75
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 35 (MN - RSV/A)	0.39 Fold Ratio Interval 0.36 to 0.42	0.40 Fold Ratio Interval 0.37 to 0.43
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 60 (MN - RSV/A)	0.21 Fold Ratio Interval 0.2 to 0.23	0.27 Fold Ratio Interval 0.25 to 0.3
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 90 (MN - RSV/A)	0.13 Fold Ratio Interval 0.12 to 0.14	0.17 Fold Ratio Interval 0.15 to 0.19
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 112/120 (MN - RSV/A)	0.08 Fold Ratio Interval 0.07 to 0.09	0.10 Fold Ratio Interval 0.09 to 0.12
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 180 (MN - RSV/A)	0.03 Fold Ratio Interval 0.02 to 0.03	0.05 Fold Ratio Interval 0.04 to 0.07
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 14 (MN - RSV/B)	0.55 Fold Ratio Interval 0.48 to 0.65	0.66 Fold Ratio Interval 0.57 to 0.76
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 35 (MN - RSV/B)	0.39 Fold Ratio Interval 0.31 to 0.5	0.34 Fold Ratio Interval 0.28 to 0.4
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 60 (MN - RSV/B)	0.17 Fold Ratio Interval 0.12 to 0.23	0.22 Fold Ratio Interval 0.16 to 0.29
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 90 (MN - RSV/B)	0.11 Fold Ratio Interval 0.07 to 0.15	0.16 Fold Ratio Interval 0.11 to 0.24
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 112/120 (MN - RSV/B)	0.07 Fold Ratio Interval 0.05 to 0.08	0.08 Fold Ratio Interval 0.06 to 0.12
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 180 (MN - RSV/B)	0.03 Fold Ratio Interval 0.01 to 0.05	0.05 Fold Ratio Interval 0.03 to 0.08
Infant: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMR Day 14 (Anti-F IgG)	0.67 Fold Ratio Interval 0.65 to 0.69	0.69 Fold Ratio Interval 0.65 to 0.72

SECONDARY outcome

Timeframe: At Delivery

Length of Infant participants measured at delivery expressed in centimeters

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Mean Length of Participants at Birth	50.04 centimeters Standard Deviation 2.921	50.16 centimeters Standard Deviation 3.144

SECONDARY outcome

Timeframe: At Delivery

Weight of infant participants measured at delivery expressed in kilograms.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Mean Weight of Participants at Birth	3.21 kg Standard Deviation 0.484	3.20 kg Standard Deviation 0.505

SECONDARY outcome

Timeframe: At Delivery

Frontal-occipital Head Circumference measured in infant participants at delivery expressed as centimeters

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Mean Frontal-occipital Head Circumference of Participants at Birth	34.2 centimeters Standard Deviation 2.08	34.2 centimeters Standard Deviation 1.77

SECONDARY outcome

Timeframe: At Delivery

The APGAR test measures the infant's Appearance, Pulse, Grimace, Activity, and Respiration. Any score of 7 or above is considered a good APGAR score. The maximum APGAR score is 10 and the minimum score is 1.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Mean APGAR (Appearance, Pulse, Grimace, Activity, Respiration) Score of Participants at Birth 1 minute	8.4 units on a scale Standard Deviation 1.08	8.4 units on a scale Standard Deviation 1.17
Infants: Mean APGAR (Appearance, Pulse, Grimace, Activity, Respiration) Score of Participants at Birth 5 minute	9.4 units on a scale Standard Deviation 0.78	9.4 units on a scale Standard Deviation 0.91

SECONDARY outcome

Timeframe: Day 0 to Delivery

Population: maternal safety population

Number of maternal participants with post-immunization onset of specific complications of third-trimester pregnancy and delivery including Pregnancy complications, Labor and delivery complications.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3045 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1581 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Number of Participants With Post-immunization Onset of Specific Complications of Third-trimester Pregnancy and Delivery No	2528 Participants	1295 Participants
Maternal: Number of Participants With Post-immunization Onset of Specific Complications of Third-trimester Pregnancy and Delivery No Data	13 Participants	8 Participants
Maternal: Number of Participants With Post-immunization Onset of Specific Complications of Third-trimester Pregnancy and Delivery Subjects without delivery data	16 Participants	10 Participants
Maternal: Number of Participants With Post-immunization Onset of Specific Complications of Third-trimester Pregnancy and Delivery Yes	488 Participants	268 Participants

SECONDARY outcome

Timeframe: Day 364 after delivery

Number of infants with developmental delay (a term used to describe a delay in a child's development.), as measured by the outcome of testing at 1 year, in infants of RSV F vaccinees as compared to placebo.

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=3008 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1561 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Infants: Number of Participants With Developmental Delay With any 12 months ASQ data	2707 participants	1395 participants
Infants: Number of Participants With Developmental Delay On schedule for communication	2670 participants	1387 participants
Infants: Number of Participants With Developmental Delay On schedule for Gross Motor	2535 participants	1318 participants
Infants: Number of Participants With Developmental Delay On schedule for Fine Motor	2535 participants	1318 participants
Infants: Number of Participants With Developmental Delay On Schedule for Personal-Social	2559 participants	1317 participants
Infants: Number of Participants With Developmental Delay On schedule for Problem Solving	2546 participants	1325 participants

SECONDARY outcome

Timeframe: Pre-dose to Delivery +180 days

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Immunogenicity of RSV F Vaccine and Placebo (Anti-F IgG) among Maternal Participants from Screening until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=2775 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1445 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Immunogenicity of Anti-RSV F IgG and Placebo Expressed as GMEU (Geometric Mean ELISA Units/mL) Pre-Dose	568 EU (ELISA units/mL) Interval 551.0 to 586.0	569 EU (ELISA units/mL) Interval 546.0 to 594.0
Maternal: Immunogenicity of Anti-RSV F IgG and Placebo Expressed as GMEU (Geometric Mean ELISA Units/mL) Day 14	10568 EU (ELISA units/mL) Interval 10249.0 to 10897.0	563 EU (ELISA units/mL) Interval 539.0 to 587.0
Maternal: Immunogenicity of Anti-RSV F IgG and Placebo Expressed as GMEU (Geometric Mean ELISA Units/mL) Delivery	8164 EU (ELISA units/mL) Interval 7944.0 to 8390.0	525 EU (ELISA units/mL) Interval 504.0 to 547.0

SECONDARY outcome

Timeframe: Pre-dose to Delivery +180 days

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery.

Immunogenicity of RSV F Vaccine and Placebo (Palivizumab-competitive antibodies (PCA)) among Maternal Participants from Screening until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=2775 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=1445 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMC (Geometric Mean Concentration) Pre-Dose	13 µg/mL Interval 13.0 to 13.0	13 µg/mL Interval 13.0 to 14.0
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMC (Geometric Mean Concentration) Delivery	130 µg/mL Interval 127.0 to 133.0	12 µg/mL Interval 12.0 to 13.0
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMC (Geometric Mean Concentration) Day 14	162 µg/mL Interval 158.0 to 167.0	13 µg/mL Interval 12.0 to 13.0

SECONDARY outcome

Timeframe: Pre-dose to Delivery +180 days

Population: The analysis population includes maternal participants who received a study injection as randomized and ≥ 2 weeks prior to delivery. Per-Protocol Immunogenicity Maternal (PP-IMM-M) participant population is analyzed.

Immunogenicity of RSV F Vaccine and Placebo (RSV/A microneutralization titers expressed as GMT) among Maternal Participants from Screening until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=879 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=489 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT (Geometric Mean Titers) Day 14	1622 titers Interval 1384.0 to 1900.0	654 titers Interval 565.0 to 756.0
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT (Geometric Mean Titers) Delivery	1569 titers Interval 1488.0 to 1654.0	663 titers Interval 616.0 to 713.0
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMT (Geometric Mean Titers) Pre-Dose	714 titers Interval 677.0 to 753.0	741 titers Interval 691.0 to 794.0

SECONDARY outcome

Timeframe: Pre-dose to Delivery +180 days

Immunogenicity of RSV F Vaccine and Placebo (RSV/B microneutralization titers expressed as GMT) among Maternal Participants from Screening until Delivery

Outcome measures

Outcome measures
Measure	Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=879 Participants Maternal participants were administered with the adjuvanted RSV F vaccine (120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Formulated Buffer (Placebo Control) n=489 Participants Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMTs Pre-Dose	563 titers Interval 525.0 to 605.0	605 titers Interval 552.0 to 664.0
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMTs Day 14	2419 titers Interval 1934.0 to 3025.0	845 titers Interval 670.0 to 1066.0
Maternal: Immunogenicity of RSV F Vaccine and Placebo Expressed as GMTs Delivery	1213 titers Interval 1138.0 to 1293.0	534 titers Interval 487.0 to 586.0

Adverse Events

Maternal ; Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum)

Serious events: 1356 serious events

Other events: 361 other events

Deaths: 0 deaths

Maternal ; Formulated Buffer (Placebo Control)

Serious events: 684 serious events

Other events: 185 other events

Deaths: 0 deaths

Infant ; Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum)

Serious events: 2535 serious events

Other events: 3167 other events

Deaths: 0 deaths

Infant ; Formulated Buffer (Placebo Control)

Serious events: 1396 serious events

Other events: 1598 other events

Deaths: 0 deaths

Serious adverse events

Other adverse events

Other adverse events
Measure	Maternal ; Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=4636 participants at risk；n=3045 participants at risk Maternal participants were administered with the adjuvanted RSV F vaccine 120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum (as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle.	Maternal ; Formulated Buffer (Placebo Control) n=4636 participants at risk；n=1581 participants at risk Maternal participants were administered with the formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.	Infant ; Adjuvanted RSV F Vaccine (120 µg RSVF Protein Adsorbed to a 0.4 mg Dose of Aluminum) n=4569 participants at risk；n=3008 participants at risk Infants in which mother received RSV F vaccine 120 µg RSV F protein adsorbed to a 0.4 mg dose of aluminum (as the phosphate salt) as a single 0.5 mL IM injection into the deltoid muscle..	Infant ; Formulated Buffer (Placebo Control) n=4569 participants at risk；n=1561 participants at risk Infants in which mother received formulated buffer (placebo control) as a single 0.5 mL IM injection into the deltoid muscle.
Gastrointestinal disorders Diarrhoea neonatal	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	8.4% 252/3008 • Number of events 312 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	7.4% 115/1561 • Number of events 137 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Gastrointestinal disorders Vomiting	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	5.6% 169/3008 • Number of events 211 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	5.3% 83/1561 • Number of events 92 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
General disorders Fever neonatal	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	13.3% 401/3008 • Number of events 527 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	11.1% 173/1561 • Number of events 226 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Infections and infestations Gastroenteritis	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	6.1% 182/3008 • Number of events 211 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	5.4% 84/1561 • Number of events 88 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Infections and infestations Ophthalmia neonatorum	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	6.5% 195/3008 • Number of events 213 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	6.2% 97/1561 • Number of events 109 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Infections and infestations Oral candidiasis	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	5.3% 158/3008 • Number of events 173 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	4.7% 74/1561 • Number of events 92 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Infections and infestations Otitis media	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	5.3% 159/3008 • Number of events 205 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	6.0% 94/1561 • Number of events 126 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Infections and infestations Upper respiratory tract infection	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	12.2% 367/3008 • Number of events 478 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	12.7% 198/1561 • Number of events 264 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Pregnancy, puerperium and perinatal conditions Jaundice neonatal	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	6.1% 182/3008 • Number of events 186 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	6.7% 104/1561 • Number of events 105 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Respiratory, thoracic and mediastinal disorders Cough	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	8.1% 244/3008 • Number of events 290 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	7.0% 109/1561 • Number of events 123 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Skin and subcutaneous tissue disorders Dermatitis diaper	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	14.1% 424/3008 • Number of events 520 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	13.2% 206/1561 • Number of events 241 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Skin and subcutaneous tissue disorders Eczema infantile	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	7.7% 231/3008 • Number of events 245 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	8.1% 126/1561 • Number of events 137 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Skin and subcutaneous tissue disorders Rash	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	6.7% 203/3008 • Number of events 246 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	8.6% 135/1561 • Number of events 152 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events
Nervous system disorders Headache	11.9% 361/3045 • Number of events 458 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	11.7% 185/1581 • Number of events 221 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events	— 0/0 • 1 year Serious Adverse Events Other (Not Including Serious) Adverse Events

Additional Information

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Principal investigator is a sponsor employee
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