Safety, Tolerability, and Immunogenicity Study of Homologous Ad26 Mosaic Vector Vaccine Regimens or Heterologous Ad26 Mosaic and MVA Mosaic Vector Vaccine Regimens With Glycoprotein 140 (gp140) for Human Immunodeficiency Virus (HIV) Prevention

This is a multicenter (more than 1 hospital or medical school team work on a study),
randomized (the study drug is assigned by chance), parallel group (each group of participants
will be treated at the same time), placebo-controlled (study in which the experimental
treatment or procedure is compared to a pretend treatment with no drug in it to test if the
drug has a real effect), and double-blind (neither physician nor participant knows the
treatment that the participant receives) study. All eligible participants will be randomly
assigned to receive 1 of the 8 vaccine regimens. Participants will receive study vaccines
(Ad26.Mos.HIV, MVA-Mosaic, gp140 DP, and placebo) 4 times as per assigned regimen. The study
comprises a Screening Period (up to 4 weeks), a Vaccination Period (participants will be
vaccinated at Baseline (Week 0), Week 12, Week 24 and Week 48), and a Follow-up Period (up to
48 weeks). A long-term follow-up period (approximately 2 years after Week 96) will continue
for participants randomized to the regimen subsequently selected for future studies, based on
analysis of Week 28 data. If Week 28 data are inconclusive, Week 52 data will be considered
for regimen selection. If no clear decision can be made, the extended follow-up period could
include participants from more than 1 group for assessing durability of immune responses.
Participants' safety will be monitored throughout the study.

Inclusion Criteria:

- Participant must be healthy on the basis of physical examination, medical history,
electrocardiogram (ECG) and laboratory criteria, and vital signs measurement performed
at Screening

- Participants are negative for human immunodeficiency virus (HIV) infection at
Screening

- All female participants of childbearing potential must have a negative serum (beta
human chorionic gonadotropin) at Screening, and a negative urine pregnancy test
pre-dose on Week 0, 12, 24, and 48

- A woman must agree not to donate eggs (ova, oocytes) for the purposes of assisted
reproduction until 3 months after receiving the last dose of study vaccine. A man must
agree not to donate sperm until 3 months after receiving the last dose of study
vaccine

- Participants are assessed by the clinic staff as being at low risk for HIV infection

Exclusion Criteria:

- Participant has chronic active hepatitis B or active hepatitis C, active syphilis
infection, chlamydia, gonorrhea, or trichomonas. Active syphilis documented by exam or
serology unless positive serology is due to past treated infection

- In the 12 months prior to enrollment, participant has a history of newly acquired
herpes simplex virus type 2 (HSV-2), syphilis, gonorrhea, non-gonococcal urethritis,
chlamydia, pelvic inflammatory disease, trichomonas, mucopurulent cervicitis,
epididymitis, proctitis, lymphogranulomavenereum, chancroid, or hepatitis B

- Participant has any clinically significant acute or chronic medical condition that in
the opinion of the investigator would preclude participation (for example, history of
seizure disorders, bleeding/clotting disorder, autoimmune disease, active malignancy,
poorly controlled asthma, active tuberculosis or other systemic infections)

- Participant has had major surgery within the 4 weeks prior to study entry or planned
major surgery through the course of the study

- Participant has had a thyroidectomy, or thyroid disease requiring medication during
the last 12 months

- Participant has a history of myocarditis, pericarditis, cardiomyopathy, congestive
heart failure with permanent sequelae, clinically significant arrhythmia (including
any arrhythmia requiring medication, treatment, or clinical follow up)

- Participant has an ECG (per examination and interpretation of a cardiologist) with
clinically significant findings, or features that would interfere with the assessment
of myo/pericarditis, including any of the following: a) conduction disturbance
(complete left or complete right bundle branch block or nonspecific intraventricular
conduction disturbance with QRS >=120 millisecond [ms], PR interval >=220 ms, any 2nd
or 3rd degree AV block, or QTc prolongation [>450 ms]); b) significant repolarization
(ST segment or T wave) abnormality; c) significant atrial or ventricular arrhythmia,
frequent atrial or ventricular ectopy (for example frequent premature atrial
contractions, 2 premature ventricular contractions in a row); d) ST elevation
consistent with ischemia, or evidence of past or evolving myocardial infarction

- Participant has a history of anaphylaxis or other serious adverse reactions to
vaccines or vaccine products, or neomycin or streptomycin or egg products