Development of a prophylactic Ebola vaccine using an heterologous prime-boost regimen: phase II


Between them, the EBOVAC 1 and 2 projects are assessing, through clinical trials in Europe and Africa, the safety and tolerability of the ‘prime-boost’ Ebola vaccine regimen, in which patients are first given a dose to prime the immune system, and then a boost dose which is intended to enhance the immune response over time. As such it contributes to broader efforts to ensure that future outbreaks of Ebola can be tackled speedily.

Vaccine development

There are currently no licensed vaccines for Ebola. However, there are a number of vaccine candidates in development. EBOVAC 1 and 2 are two of three projects in the IMI Ebola+ programme that are generating the data needed to assess the safety and immunogenicity of different vaccine candidates and the level and duration of protection they actually offer against the disease.

Between them, the two EBOVAC projects are assessing, through clinical trials in Europe and Africa, the safety and tolerability of the ‘prime-boost’ Ebola vaccine regimen (Ad26.ZEBOV and MVA-BN-Filo) in development at the Janssen Pharmaceutical Companies of Johnson & Johnson. In a prime-boost vaccine regimen, patients are first given a dose to prime the immune system, and then a boost dose which is intended to enhance the immune response over time.

Phase I trials are carried out by the EBOVAC1 project. These trials will gather preliminary information on the safety and tolerability of the vaccine regimen. The immune response generated by the regimen will also be evaluated longer term.

Subject to review of the preliminary Phase I data, the Phase II and III trials, will be carried out in parallel by the EBOVAC2 and EBOVAC1 projects respectively to speed up the clinical development of the vaccine regimen. In these trials, larger groups of people will receive the vaccine regimen, allowing the projects to gather further information on the regimen’s safety and immunogenicity, including in specific groups such as children and the elderly, and to assess its efficacy against Ebola virus.

A part of the Ebola+ Programme

The IMI Ebola+ programme was launched in response to the Ebola virus disease (EVD) outbreak that started in western Africa in 2014. The comprehensive programme contributes to efforts to tackle a wide range of challenges in Ebola research, including vaccines development, clinical trials, and transport, as well as diagnostics. The programme complements work being carried out with the support of other funding bodies. In addition to Ebola, the programme will also address related diseases, such as Marburg.

About Ebola and related diseases

Ebola virus disease (EVD), previously known as Ebola haemorrhagic fever, is a rare and deadly disease caused by infection with one of the Ebola virus strains. The virus spreads in the human population through direct human-to-human contact with the bodily fluids of infected patients who are showing symptoms. It has an incubation period of 2-21 days, and it usually begins with flu-like symptoms, but rapidly progresses to multiple organ failure and blood-clotting abnormalities which manifest as internal and external haemorrhages (bleeding). It is fatal in between 25% and 90% of cases. There is currently no licensed treatment against EVD, and the development of treatments and preventive measures such as vaccines is hampered by challenges including manufacturing-related hurdles, the stability of vaccines during transport and storage, vaccine deployment, and the time taken to diagnose cases of EVD.

Ebola is a member of the filovirus family of viruses, which also includes Marburg virus. Like Ebola, Marburg causes cause severe, often fatal haemorrhagic fever in humans and other primates (monkeys, gorillas and chimpanzees), and like Ebola, it is transmitted directly from one person to another. (In contrast, other viruses that cause haemorrhagic fevers are spread via intermediate hosts - for example, dengue fever is transmitted by mosquitoes.) There is no specific treatment or vaccine against Marburg haemorrhagic fever.

The 2014-15 Ebola epidemic was unprecedented in its scale and geographical distribution. By the middle of 2015, World Health Organization (WHO) statistics recorded over 27 000 cases and 11 000 deaths from the disease, most of them in Guinea, Liberia, and Sierra Leone. The epidemic highlighted the need for research into better vaccines, diagnostics and treatments to stop future epidemics in their tracks.

Achievements & News

Two-dose Ebola vaccine is safe, induces robust immune response in adults with HIV

Data published in the journal PLOS Medicine demonstrates that the IMI-funded Johnson & Johnson Ebola vaccine regimen was well tolerated and induced a robust immune response in both healthy adults and adults living with HIV. ###The data is from a Phase 2 study conducted in Burkina Faso, Cote d’Ivoire, Kenya and Uganda that enrolled 668 healthy adults and 142 adults living with HIV.

The study also confirms that HIV infection (well-controlled via treatment with a highly-active antiretroviral therapy) did not have any apparent influence on the immune responses elicited by the vaccine regimen.

‘These data add to the growing body of evidence supporting the prophylactic use of the Johnson & Johnson Ebola vaccine regimen to protect people at risk of Ebola. This is critical to our vision of protecting some of the world’s most vulnerable and underserved people – including people living with HIV – by preventing Ebola outbreaks before they start,’ said Paul Stoffels of Johnson & Johnson. 

Find out more

Preparedness key to preventing Ebola outbreaks, says top African scientist Nicolas Meda

In 2014, an Ebola outbreak kicked off in the west African nation of Guinea and quickly spread to Sierra Leone and Liberia, putting other countries in the region on high alert. Epidemiologist and public health expert Professor Nicolas Meda of Burkina Faso played a key role in his country’s response to the epidemic, and participated in the IMI Ebola vaccine project EBOVAC2.### In an interview with the IMI Programme Office, he looks back on the experience and sets out the lessons learnt and actions taken since then to prevent future outbreaks. In the interview, he also highlights the benefits of participating in IMI. ‘In EBOVAC2, it’s pretty much a global collaboration. So this is a challenge and an opportunity to improve our knowledge and our skills on the conduct of vaccine trials,’ he explains. ‘Because as I said, we did a lot of clinical trials, but they were for medicines. This time it was a trial for a vaccine and this experience was important and exciting for the team.’ He also urges countries to boost the capacity of their health systems. ‘At the political level there are measures that every country should put in place to be able to do surveillance well and detect cases early,’ he insists. ‘If you detect early, you have a good chance of limiting the epidemic. But if you don’t have this capacity in the health system to do surveillance and detect early, you will always have big epidemics that spread. So strengthening health systems so that they are capable of detecting and responding rapidly is essential.’

EBOVAC2 clinical trials underway in France

IMI Ebola project EBOVAC2 has launched a campaign in France to recruit around 300 volunteers for a trial Ebola vaccine regimen. The goal of this study is to assess the safety and efficacy of a novel prime boost preventive regimen against Ebola virus disease.### The vaccine regimen under investigation has two parts – a ‘prime’ vaccine to stimulate the immune system and a ‘boost’ vaccine to strengthen and extend the immune response. Additional volunteers are being recruited in the UK and in Africa. ‘Participants in this trial cannot become infected with the Ebola virus,' said EBOVAC2 project coordinator Rodolphe Thiébaut of INSERM. ‘Only synthetic proteins or parts of proteins are used in the various vaccines being tested. They cannot in any way cause infection. This is based on the same principle as many existing vaccines for infectious diseases.’


  Show participants on map
EFPIA companies
  • Janssen Vaccines & Prevention BV, Leiden, Netherlands
Universities, research organisations, public bodies, non-profit groups
  • Centre Muraz, Bobo Dioulasso, Burkina Faso
  • Institut National De La Sante Et De La Recherche Medicale, Paris, France
  • London School Of Hygiene And Tropical Medicine Royal Charter, London, United Kingdom
  • University of Oxford, Oxford, United Kingdom
Small and medium-sized enterprises (SMEs) and mid-sized companies (<€500 m turnover)
  • Inserm Transfert SA, Paris, France
Third parties
  • Chu Hopitaux De Bordeaux, Talence, France
  • Universite De Bordeaux, Bordeaux, France
  • Universite Paris Xii Val De Marne, Creteil cedex, France

NameEU funding in €
Centre Muraz3 782 783
Inserm Transfert SA427 090
Institut National De La Sante Et De La Recherche Medicale15 057 161
London School Of Hygiene And Tropical Medicine Royal Charter908 453
University of Oxford2 041 083
Third parties
NameFunding in €
Chu Hopitaux De Bordeaux329 250
Universite De Bordeaux120 000
Universite Paris Xii Val De Marne125 000
Total Cost22 790 820