EBOla Post-Exposure Prophylaxis

EBO-PEP is a multicentre, multi-epidemic, phase III, comparative, controlled, randomised, strict superiority trial in two unblinded parallel arms.

The trial will be open during EVD epidemics and will recruit asymptomatic participants at high risk of developing EVD.

Participants will be randomized (1:1) into one of two trial arms:

* Arm 1 (ERV): Ervebo D0 (72 million PFU IM) * Arm 2 (ERV+IMZ): Ervebo D0 (72 million PFU IM) + Inmazeb IV (150 mg/kg) D0 + Ervebo D56 (revaccination)

Definition of high-risk:

Direct contact with a person with EBOV PCR-confirmed EVD with diarrhea, vomiting or external bleeding ("wet symptoms"), or with their body fluids; Direct contact with the dead body of a person with confirmed or probable EVD; Needlestick with a syringe contaminated by the blood of a person with confirmed or probable EVD; Or a child born to or breastfed by an individual with EVD

Trial follow-up All participants are monitored daily for a minimum of 21 days.

Some visits are conducted in person at the investigation site, also called the Post-Exposure Prophylaxis (PEP) center:

* at Day 5, Day 10, and Day 21 for the ERV arm, * at Day 5, Day 10, Day 21, and Day 56 for the ERV+IMZ arm. Other visits are conducted at home or by phone, in collaboration with the Ministry of Health's surveillance team.

Participants in the ERV+IMZ arm have an in-person visit at Day 56 to be revaccinated with the Ervebo vaccine to compensate for potential inhibition of the vaccine response when Ervebo is administered simultaneously with Inmazeb.

Participants in the ERV arm have a phone visit at Day 56. For all participants, a phone visit is scheduled at Day 60. It corresponds to the last visit for all trial participants.

Follow-up in Case of Hospitalisation In case of clinical signs suggestive of EVD, participants enter the suspected case management pathway at the Ebola Treatment Center (ETC).

If EVD is confirmed by EBOV PCR, participants are allowed at the ETC, and their study samples are discontinued. They continue to be followed by the research team, and daily data are collected throughout their stay at the ETC until they are discharged alive or deceased. The day of discharge from the ETC marks the end of follow-up in the study for these participants.

Of note, participants in the ERV+IMZ arm who have confirmed EVD are not revaccinated at day 56.

Of note, participants in the ERV+IMZ arm who have confirmed EVD are not revaccinated at day 56.

If EVD is not confirmed, participants continue to be followed up by the PEP center according to the protocol.