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


Start Date
End Date
IMI2 - Call 2
Grant agreement number

IMI Funding
58 292 722
EFPIA in kind
33 745 758
Total Cost92 038 481


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 will be 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

Ebola vaccine immune response lasts at least 1 year
March 2017

The immune response triggered by Johnson & Johnson’s two-part ‘prime boost’ Ebola vaccine regimen appears to last at least one year, according to a new study published in the Journal of the American Medical Association (JAMA). The research was funded in part by IMI’s EBOVAC1 project. The west African Ebola outbreak, which infected 28 000 people and killed over 11 000, ###highlighted the urgent need for a vaccine against the disease. The vaccine regimen is being developed by Janssen Vaccines, one of the Janssen Pharmaceutical Companies of Johnson & Johnson, in collaboration with Bavarian Nordic. It consists of an initial vaccine dose to prime the immune system, followed by a boost dose of another vaccine which is intended to enhance the immune response over time. Trials of the regimen are taking place in Europe, Africa, and the US. This latest study focuses on a Phase I trial in Oxford, UK, in which 75 healthy volunteers received the vaccine regimen. Of the 64 people who attended the one-year follow-up, all had high levels in their blood of Ebola virus glycoprotein-specific antibodies; these antibodies appear to play an important role in immunity to the disease. ‘The world needs a vaccine to help prevent or mitigate future Ebola outbreaks, and ideally it should provide sustained protection for at-risk populations,’ said Johnson & Johnson Chief Scientific Officer Paul Stoffels. ‘We are committed to helping the global community finish the job of finding an Ebola vaccine. Together with our consortium partners the London School of Hygiene & Tropical Medicine, University of Oxford, and Inserm, we are grateful for the ongoing support of Europe’s Innovative Medicines Initiative (IMI), BARDA and NIH.’

IMI Ebola vaccine project publishes positive data
April 2016

Data from an early stage clinical trial of a novel Ebola vaccine regimen show that it produces a long-lasting immune response and is well tolerated, with minimal side effects. The study, supported in part by IMI through the Ebola+ project EBOVAC1, is published in the Journal of the American Medical Association (JAMA).### In the trial, healthy volunteers in the UK received a two-part ‘prime boost’ regimen comprising an initial vaccine dose to ‘prime’ the immune system and a subsequent dose of a different vaccine to ‘boost’ the immune response. Significantly, eight months after immunisation, 100% of those vaccinated still had Ebola-specific antibodies. This long-term protection is important. ‘Recent evidence highlighting the persistence of the Ebola virus in bodily fluids, and the potential for sexual transmission from Ebola survivors, reinforce the importance of finding a robust and durable vaccine for this disease,’ explains Matthew Snape of the Oxford Vaccine Group and the study’s lead author. In total, 10 clinical studies on this regimen are taking place in Europe, Africa and the US. The west African Ebola outbreak has infected over 28 600 people and killed more than 11 300. Flare-ups continue to occur in the region due to the persistence of the virus among survivors.

EBOVAC trial in Sierra Leone starts; boosts local health infrastructure
October 2015

A clinical trial of an investigational Ebola vaccine regimen is now underway in Kambia, Sierra Leone thanks to the IMI projects EBOVAC1, EBODAC and EBOMAN. ###

Even in the short term, the benefits to the local community of the ‘EBOVAC-Salone’ trial are immense; new facilities had to be built to run the study, including the first emergency room at the local district hospital, and a vaccine storage facility. In addition, the project provides both jobs and training for local healthcare workers, who will also gain valuable experience by working on the trial. In the longer term, the community may also benefit if the vaccine regimen is approved.

Sierra Leone was at the epicentre of the Ebola outbreak, with 14 000 cases and 4 000 deaths, including many healthcare workers.  The vaccine regimen under investigation is a ‘prime-boost’ regimen, in which two doses are given several weeks apart. The first dose ‘primes’ the immune system, while the second ‘boost’ reinforces its effects with the goal of potentially strengthening and optimising the duration of the immunity. The study is notable in that it will evaluate the vaccine regimen’s safety and immune response within the general population of Sierra Leone, including vulnerable groups such as adolescents and children. The vaccine regimen is also in trials in other parts of Africa, Europe and the US.

The EBOVAC-Salone trial is working closely with the IMI project EBODAC, which aims to ensure the prime-boost vaccine regimen is well accepted and successfully deployed. It is doing this by informing local engagement strategies, designing graphical communication aids, deploying technological solutions to increase compliance and uniquely identifying trial participants.

IMI-supported Ebola vaccine trials get underway in Africa
April 2015

A clinical trial of an Ebola vaccine regimen run through the IMI project EBOVAC1 has started in Kenya and Uganda. The trials are Phase I studies designed to evaluate the safety of the vaccine regimen and evaluate the long-term immune response to a regimen developed at the Janssen Pharmaceutical Companies of Johnson and Johnson.### In each of the Phase I trial sites, 36 healthy adult volunteers receive either a placebo, or a two-part ‘prime-boost’ vaccine regimen, comprising an initial dose to prime the immune system and a ‘boost’ to enhance the immune response in the longer term. Similar studies are already underway in the UK and US and further studies in Africa, including in Sierra Leone, are anticipated to receive approval soon. The EBOVAC1 project is part of IMI’s wider Ebola+ programme, which currently covers vaccines and diagnostics and it is hoped will deliver results that will contribute to efforts to tackle both the current and future outbreaks.

According to WHO reports, as of mid-April there had been over 25 000 confirmed, probable, and suspected cases of Ebola in the current outbreak and over 10 000 deaths, most of them in Guinea, Liberia, and Sierra Leone

Participants Show participants on map

EFPIA companies
  • Janssen Vaccines & Prevention B.V, Leiden, Netherlands
Universities, research organisations, public bodies, non-profit groups
  • Institut National De La Sante Et De La Recherche Medicale, Paris, France
  • London School of Hygiene and Tropical Medicine, London, United Kingdom
  • University of Oxford, Oxford, United Kingdom


Project coordinator
Deborah Watson-Jones
London School of Hygiene and Tropical Medicine
+255 (0) 28 250 0019
EFPIA lead
Macaya Douoguih
Janssen Vaccines & Prevention B.V
Leiden, Netherlands