A Study of a 2-dose Ebola Vaccine Regimen of Ad26.ZEBOV Followed by MVA-BN-Filo in Healthy Pregnant Women

The purpose of this study is: a) to assess adverse maternal/fetal outcomes in pregnant women randomized to receive the 2- dose Ebola vaccine regimen (Ad26.ZEBOV, MVA-BN-Filo \[Group A\]) and in control women (unvaccinated pregnant women \[Group B\]); and b) to assess adverse neonatal/infant outcomes in neonates/infants born to women randomized to receive the 2-dose Ebola vaccine regimen (Ad26.ZEBOV, MVA-BN-Filo \[Group A\]) and in neonates/infants born to control women (unvaccinated during pregnancy \[Group B\]).


Eligibility Criteria:
Inclusion Criteria:

* Healthy on the basis of physical examination, medical history, obstetric history, and vital signs performed at screening
* Healthy on the basis of clinical laboratory tests performed at screening
* Confirmed singleton pregnancy by positive urine human chorionic gonadotropin (HCG) and ultrasound at time of screening and informed consent, and reconfirmed pregnancy via ultrasound at Randomization/Day 1
* Residing within catchment area of the study site
* Evidence of normal progress of gestation prior to Randomization (Day 1) based on obstetric evaluation (including obstetric history, obstetric examination and fetal ultrasound)

Exclusion Criteria:

* History of Ebola Virus Disease (EVD) (self-declared or laboratory confirmed)
* Has received any experimental candidate Ad26- or MVA-based vaccine in the past
* Known allergy or history of anaphylaxis or other serious adverse reactions to vaccines or vaccine products (including any of the constituents of the study vaccines \[for example, polysorbate 80, ethylenediaminetetraacetic acid (EDTA) or L-histidine for Ad26.ZEBOV vaccine; tris (hydroxymethyl)-amino methane (THAM) for MVA-BN-Filo vaccine\]), including known allergy to egg, egg products, chicken proteins and aminoglycosides
* Participant with acute illness (this does not include minor illnesses such as diarrhea or mild upper respiratory tract infection) or body temperature greater than or equal to (\>=)38.0ºC on Day 1 will be excluded from enrollment at that time but may be rescheduled for enrollment at a later date
* During the 6 weeks prior to screening, have had any of (a) confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (COVID-19) infection (test positive), OR (b) suspected SARS-CoV-2 infection (clinical features without documented test results), OR (c) close contact with a person with known or suspected SARS-CoV-2 infection
* Obstetric history including: a. \>= 2 consecutive spontaneous abortions, b. history of pre-eclampsia or eclampsia, c. rhesus negative multigravida, d. grand multigravida (greater than \[\>\] 5 previous pregnancies, e. previous late still birth (defined as loss of pregnancy at any time after 28 weeks gestation), f. previous low birth weight baby or premature delivery (defined as a delivery before 37 weeks gestation), g. previous neonatal death (defined as death of an infant within the first 28 days of life), h. previous delivery of an infant with a known or suspected genetic or chromosomal abnormality, i. history of other significant pregnancy-related or neonatal complications judged likely to affect the safety of the mother or infant or to significantly compromise the endpoint data collected