A Study to Learn About the Vaccine RSVpreF In Pregnant Participants With HIV and Their Infants

Local reactions included redness, swelling, and pain at injection site and were recorded in electronic diary (e-diary). Redness and swelling were measured by the maternal participant and recorded in measuring device units (mdu) in the e-diary (range: 1 to 21). 1 mdu = 0.5 centimetre (cm). Redness and swelling were graded as mild (>2.0 to 5.0 cm), moderate (>5.0 to 10.0 cm), severe (>10.0 cm) and grade 4 (necrosis or exfoliative dermatitis for redness and necrosis for swelling). Pain at injection site was graded as mild (did not interfere with activity), moderate (interfered with activity), severe (prevented daily activity) and grade 4 (emergency room visit or hospitalization for severe pain at the injection site). Grade 4 reactions were classified by the investigator or medically qualified designee.

Systemic events included fever, fatigue, headache, nausea, muscle pain, joint pain, vomiting and diarrhea and were recorded by participants in the e-diary. Fever was defined as an oral temperature greater than or equal to (>=) 38.0 degree Celsius (C) and classified as mild (38.0 to 38.4 degree C), moderate (38.5 to 38.9 degree C), severe (39.0 to 40.0 degree C) and grade 4 (>40.0 degree C). Headache, nausea, fatigue, muscle pain and joint pain were graded as mild (did not interfere with activity), moderate (some interference with activity), severe (prevented daily activity). Vomiting: mild (1-2 times in 24 hours [H]), moderate (>2 times in 24 H), severe (required intravenous [IV] hydration). Diarrhea: mild (2-3 loose stools in 24 H), moderate (4-5 loose stools in 24 H), severe (>=6 loose stools in 24 H). For all systemic events except fever, Grade 4= emergency room visit or hospitalization. Grade 4 events were classified by investigator or medically qualified designee.

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included in this outcome measure.

AESIs are a subset of targeted medical events based on review of known pharmacology, toxicology findings, possible class effects, published literature, and signals arising from safety data assessments, and on population under study. AESIs were based on targeted medical events associated with pregnant maternal participants prior to/during delivery and post delivery. For maternal participants, the following were considered as protocol defined AESIs: diagnosis of Guillain-Barré syndrome; diagnosis of acute polyneuropathy without an underlying etiology; hypertensive disorders of pregnancy; preterm delivery (delivery at <37 0/7 weeks' gestation) and atrial fibrillation. AESIs was to be recorded as an AE or serious adverse event (SAE) on the case report form (CRF).

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An SAE was any untoward medical occurrence that at any dose: resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in congenital anomaly/birth defect or that was considered an important medical event.

AESIs are a subset of targeted medical events based on review of known pharmacology, toxicology findings, possible class effects, published literature, and signals arising from safety data assessments, and on population under study. AESIs were based on targeted medical events associated with infants at birth. For infant participants the following were considered as protocol defined AESIs: preterm birth (born at <37 0/7 week's gestation); birth weight 1001-2500 grams (g); developmental delay. Extremely preterm birth (born at <28 0/7 week's gestation) and extremely low birth weight (less than or equal to [<=] 1000 g) were reported as serious AESIs.

Neonatal death was defined as the death of a live-born infant that occurred within a month after birth.

Congenital malformations/anomalies were defined as structural or functional anomalies that occurred during intrauterine life and could be identified prenatally, at birth or later in life.

Other neonatal problem included dysmaturity, neonatal illness, hospitalization, and drug therapies.

APGAR was a fast evaluation technique used to evaluate a newborn baby's overall health. APGAR stands for (A) Appearance (skin coloration), (P) Pulse (heart rate), (G) Grimace (reflex response), (A) Activity (muscle tone) and (R) Respiration (breathing). Each component was given a score of 0, 1, or 2; after summing up scores for each component a total possible score was of 0 (worst condition) to 10 (best condition), where higher scores indicate better health. A score of 7 to 10 was good, 4 to <7 was moderate, and <4 was poor.

APGAR was a fast evaluation technique used to evaluate a newborn baby's overall health. APGAR stands for (A) Appearance (skin coloration), (P) Pulse (heart rate), (G) Grimace (reflex response), (A) Activity (muscle tone) and (R) Respiration (breathing). Each component was given a score of 0, 1, or 2; after summing up scores for each component a total possible score was of 0 (worst condition) to 10 (best condition), where higher scores indicate better health. A score of 7 to 10 was good, 4 to <7 was moderate, and <4 was poor.

APGAR was a fast evaluation technique used to evaluate a newborn baby's overall health. APGAR stands for (A) Appearance (skin coloration), (P) Pulse (heart rate), (G) Grimace (reflex response), (A) Activity (muscle tone) and (R) Respiration (breathing). Each component was given a score of 0, 1, or 2; after summing up scores for each component a total possible score was of 0 (worst condition) to 10 (best condition), where higher scores indicate better health. A score of 7 to 10 was good, 4 to <7 was moderate, and <4 was poor.

GA at birth was collected as:>=24 to <28 weeks, >=28 to <34 weeks, >=34 to <37 weeks, >=37 to <42 weeks, and >=42 weeks.

Length of hospitalization at birth refers to the amount of time the infant remains admitted to the healthcare facility immediately following delivery and if that length of time is greater than or less than 72 hours. Postnatal standard of care procedures in South Africa were as follows: healthy newborns and their mothers were typically discharged within 24 hours after an uncomplicated vaginal delivery, or within 72 hours following an uncomplicated Caesarean section. These practices were supported by the Guidelines for Maternity Care in South Africa.

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention.

An AE was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. An SAE was any untoward medical occurrence that at any dose: resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, resulted in congenital anomaly/birth defect or that was considered an important medical event.

An NDCMC was defined as a disease or medical condition, not previously identified, that was expected to be persistent or otherwise long-lasting in its effects. NDCMCs were reported as both AEs and SAEs.

GMTs and the corresponding 2-sided 95% confidence intervals (CIs) were calculated by exponentiating the mean logarithm of the neutralizing titers and the corresponding CIs based on the Student t distribution.

GMFRs and the corresponding 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the fold rises and the corresponding CIs based on the Student t distribution. The GMFR for each vaccine group was defined as the geometric mean of the fold rises in the assay results from the specified time points.