Clinical Research Directory

Immunology of Ebola Vaccine

In this study 30 healthy adult participants will receive a single dose of an Ebola vaccine. Blood samples, fine needle aspirates, core biopsies, and bone marrow aspirates will be collected prior to and following vaccination to assess immune responses in the blood, lymph nodes, and bone marrow over multiple time points.

Impact of Delay Between Administration of Inmazeb Administration and Vaccination by Ervebo on Vaccine Immune Response on Healthy Volunteers

Ebola virus disease (EVD) is emerging regularly in various African countries for various reasons: during contact with mortal remains, during an unsafe burial or following the viral dissemination around a recovered patient. However, tools to fight the spread of the disease are being made available to countries affected by EVD. A vaccine (Ervebo), developed by the Merck laboratory, demonstrated its efficacy in protecting contacts and contacts of contacts in the "Ebola That's Enough" trial and two monoclonal antibodies (Mabs) have demonstrated their efficacy in reducing mortality in patients with EVD: REGN-E3B (Inmazeb) and Mab114 (Ebanga). The question of their use in post-exposure prophylaxis (PEP), defined as the treatment of contacts at very high risk of contracting EVD, is essential. Vaccination with Ervebo does not appear to be a good standalone option for PEP, particularly because antibody synthesis is delayed, and the vaccine is likely to be inactive for 10 days after administration. Monoclonal antibodies, on the other hand, seem to be a promising avenue in this indication because of their rapid action on the inhibition of virus entry into the cell. Moreover, Ervebo vaccine expresses the viral target recognized by mAbs, GP EBOV. It is therefore possible that the vaccine response (production of vaccine antibodies) is inhibited by mAbs, which bind to GP EBOV and prevent vaccine replication, particularly in the case of concomitant administration. However, no data on vaccine efficacy in combination are available. The question of the interaction between the monoclonal antibody and Ervebo and the delay between the administration of these two strategies remains unresolved. The hypothesis of this trial is that Ervebo vaccine efficacy is diminished with the concomitant administration of a monoclonal antibody, especially if this administration is close (short time between Mabs and vaccination). We hypothesize that with an optimal delay between Mabs and vaccination, the immunogenicity of the vaccine when administered with monoclonal antibodies could be non-inferior to the vaccine alone, thus providing optimal short and long term protection. The main objective of this study is to evaluate the extent of effect, if any, of Inmazeb administration on vaccine-induced neutralizing antibody responses to Zaire Ebola virus by Ervebo vaccine. If an interaction is observed, this will possibly enable determination of the time interval required between the administration of Inmazeb and Ervebo vaccine. The trial will have 6 arms. A control arm of vaccination alone will serve to characterize the immune response to the vaccine and it will be used as a comparator of vaccine immune response in the intervention arms. A control arm of mAb alone will serve to characterize the pharmacokinetic profile of mAb in the Guinean population. The 4 arms including different doses of Inmazeb plus vaccination were designed to mimic a time interval between Ervebo and Inmazeb administration (15, 57 and 169 days after Inmazeb).

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.

REVIVE (Response to the Ebola Virus Vaccine)

This study is a vaccine-related clinical trial which will be conducted by our study team at Kenema Government Hospital (KGH)'s Viral Hemorrhagic Fever Program in collaboration with Tulane University School of Medicine. This study is funded by Merck \& Co., the developers of ERVEBO®. This investigational medicinal product (IMP) was successful in Sierra Leone through the Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE) working with the College of Medical and Allied Health Services (COMAHS) at the University of Sierra Leone. ERVEBO® was also successfully tested in Liberia and the Republic of Guinea. These successful trials led to the United States Food and Drug Administration (USFDA) approval of ERVEBO®, as well as approval for therapeutic use in the Democratic Republic of the Congo, Burundi, Ghana, and Zambia. This particular vaccination study will focus on the anamnestic response to the ERVEBO® vaccine, (full name - rVSVDG-ZEBOV-GP Ebola Virus Vaccine). The original clinical trials conducted excluded Ebola Virus Disease (EVD) survivors from participating. However, with ongoing research, there is evidence of waning immune response and even recurrent infections in EVD survivors.

Safety and Immunogenicity of Ervebo® and Zabdeno® Booster Vaccines Against Ebola Virus Following Previous Vaccination with the Zabdeno/Mvabea® or Ervebo® Vaccine Schedules in DRC

The goal of this randomized controlled trial is to investigate whether individuals in DRC previously vaccinated with Zabdeno/Mvabea® or Ervebo® vaccine schedules against Ebola virus can be safely and adequately boosted with homologous or heterologous vaccine schedules. Participants will be randomized to receive either a homologous or heterologous vaccine schedule and will be asked to come to the clinic at prespecified timepoints over a period of 6 months to collect blood samples for comparison of immunological responses against Ebola virus between both schedules. Safety and tolerability of the vaccines will be evaluated by recording Adverse Events (AE's) and grading physical and vital signs evaluations.

Safety and Immunogenicity of rVSVΔG-ZEBOV-GP Vaccination When Dosed Concurrently With mRNA COVID-19 Vaccine Booster Doses

Concurrent vaccination scheduling for key target populations in Rwanda, such as healthcare workers, may confer significant advantages in the provision of vaccine coverage to several infectious diseases. This is a phase IV vaccine trial that looks to establish if two licenced vaccines, the rVSVΔG-ZEBOV-GP vaccine for protection against Ebola virus and messenger ribonucleic acid (mRNA) COVID vaccine for protection against SARS-CoV-2 virus, given concurrently to self selected healthy adult volunteers confers an acceptable safety profile and immunogenicity response.