Evaluation of a New Ebola Vaccine Using a Short-interval Prime-boost Vaccination

Ebola Virus Disease Clinical Trial

Official title: A Phase Ib Safety and Immunogenicity Clinical Trial of Heterologous Prime-boost Immunisation With ChAd3-EBO Z and MVA-EBO Z in Healthy Senegalese Adult Volunteers Aged 18-50 Years.

Status Completed

Clinical Trial Summary

This is a clinical trial in which healthy volunteers will be administered two experimental Ebola vaccines: ChAd3-EBO Z and MVA-EBO Z. Two groups of volunteers will be vaccinated with both vaccines one after the other in a prime/boost regimen.

All ChAd3-EBO Z doses are 2.5 x 10^10 - 3.7 x 10^10 vp and all MVA-EBO Z doses are 1.0 x 10^8 pfu.

All volunteers will receive a ChAd3-EBO Z priming vaccine and a MVA-EBO Z boosting vaccine 7 days later.

The site of administration of the MVA-EBO Z vaccine differs between the two groups:

Group 1 will receive the MVA-EBO Z vaccine in the same arm as the ChAd3-EBO Z vaccine.

Group 2 will receive the MVA-EBO Z vaccine in the opposite arm from the ChAd3-EBO Z vaccine.

The study will assess the safety of the vaccinations, and the immune responses to vaccination. Immune responses are measured by tests on blood samples.

The ChAd3-EBO Z and MVA-EBO Z vaccines are called viral vectored vaccines. They are made from viruses which are modified so that they cannot multiply. The viruses have extra DNA in them so that after injection, the body makes Ebola proteins (but Ebola does not develop), so that the immune system builds a response to Ebola without having been infected by it.

Healthy volunteers will be recruited in Dakar, Senegal. The study will be funded by GSK.

Clinical Trial Description

The CHUD study team will hold sensitisation meetings, in specific areas targeting specific populations, to explain the study to potential volunteers. During these meetings the investigators will explain the following: the need for a vaccine (including a simple picture of the burden of the Ebola disease and how it affects the community); the current status of vaccine development (including the fact that this is likely to be a prolonged process that probably will not influence the course of the current epidemic); the study screening and informed consent procedure; risks of vaccination and the unproven benefits of this vaccination. It will be stressed that this is an experimental vaccine and there is no current evidence that it will provide protection, and that it will therefore still be necessary to take preventive measures and to seek treatment if ill for any reason after vaccination.

After these sensitisation meetings, the CT team will actively identify. The study will be further explained to eligible participants on individual basis. Potential volunteers will be invited to the CHUD CT site for further discussion. Potential volunteers will be informed that they are free to withdraw from the CT at any time without giving any reason. Individuals who feel that the trial is appropriate for them will be invited to attend a formal screening visit.

Detailed information about the study will be provided in a Participant Information Sheet (PIS) at least 24 hours prior to the consent being undertaken. The informed consent process will start before the screening visit. The volunteer will be given the opportunity to ask about details of the trial, and will then have time to consider whether or not to participate. The investigators will ensure that the volunteers are briefed on the contents of the PIS in the language they understand. The investigators will also ensure that all volunteers fully understand the risks. Any volunteer who appears to have less than complete understanding will not be enrolled.

All volunteers will sign and date the informed consent form before any study specific procedures (including screening visit) are performed. If the volunteer is illiterate, s/he will sign the informed consent form; in the latter case a literate adult impartial witness will be present throughout the whole consenting process, write subject's name and date of signature and will sign and date the consent form. Volunteers will sign and date two copies of the consent form, one for them to take away and keep, and one to be stored in the subject's medical records.

Vaccinations in Group 1 can commence 7 days after vaccination after interim safety review of the first 5 volunteers receiving the same dose in the UK CT. The first 5 volunteers will be vaccinated in a staggered fashion.

The first volunteer to receive the ChAd63-EBO Z vaccine dose in Group 1 will be vaccinated alone and we will wait 24 hours before vaccinating subsequent volunteers in this group. Two further Group 1 volunteers will be vaccinated 24 hours after the first, and then at least another 24 hours gap will pass before vaccinating further subjects receiving the ChAd63-EBO Z vaccine in Groups 1 & 2.

The same staggered vaccine administration procedure will be adopted for vaccinations with the MVA-EBO Z vaccine. A total of 20 volunteers will be enrolled in this group.

In Group 2, vaccination can commence after 5 volunteers in Groups 1 have received the ChAd63-EBO Z vaccine dose. The same staggered vaccine administration procedure as for Group 1 will be adopted for vaccinations with the MVA-EBO Z vaccine. A total of 20 volunteers will be enrolled in this group.

Volunteers will be visited daily at home by a study field worker or nurse to record adverse events (solicited and unsolicited for six consecutive days after vaccination). Additional scheduled visits at the CHUD clinic will be at day 7, 14, 28, 35, 56, 90, 180 post-first vaccination during which interim history will be collected, physical examination and blood tests performed at the time-points indicated in the schedule of attendances. Blood will also be taken for exploratory immunology analysis.

All volunteers will be followed up for 6 months beginning from the day of the first vaccination. ;

Related Conditions & MeSH terms

• Ebola Virus Disease
• Hemorrhagic Fever, Ebola
• Virus Diseases

• NCT number: NCT02485912
• Study type: Interventional
• Source: University of Oxford
• Status: Completed
• Phase: Phase 1
• Start date: July 2015
• Completion date: January 2016