Ebola: a clinical trial in the heart of Africa
Every day, nearly 70 volunteers are seen at the two Guinean vaccination centres, managed by the non-governmental organisation Alima, Inserm's partner in the project. A report at the heart of the PREVAC clinical trial.
"A year after starting the first vaccinations, virtually all the participants have attended the various follow-up visits at the Mafèrinyah center and 95 % have attended those at Landréah. It’s quite remarkable - the participants all want to contribute to the effort to fight Ebola", emphasizes Keira Camara, investigating physician at the Landréah vaccination center in Guinea.
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The PREVAC international consortium includes Inserm, the US National Institutes of Health (NIH), the London School of Hygiene and Tropical Medicine (LSHTM) and the health authorities of the four participating countries (Guinea, Liberia, Mali and Sierra Leone). Three pharmaceutical companies supply the vaccines tested: Janssen Vaccines & Prevention, B.V. (part of the Janssen Pharmaceutical Companies of Johnson & Johnson), Bavarian Nordic and Merck Sharp & Dohme Corp. -
One of the major keys to the success of the PREVAC vaccine trial involves the participation of the local communities. Doctor Malick Minkael Sylla meets with the Mafèrinyah community counselors, who will recruit volunteers in the field. -
Thanks to the groundwork of the trial anthropologists, the community counselors step up the awareness-raising meetings in the neighborhoods. These meetings always take place in the presence of a community champion, who, due to their work or status, is listened to and respected by the local communities. -
The triage office receives the various PREVAC participants. The new volunteers are registered and the follow-up information updated for those already enrolled. In Guinea, two vaccination centers have been established: one in Conakry, in an urban area, and the other in Mafèrinyah (in this photo), in a rural area. -
In the Mafèrinyah pharmacy, Cécé Kolié and Benjamin Hamzé prepare the vaccines. The injections are determined by software which randomly determines who will receive one of the candidate vaccines and who will receive a placebo. -
20 % of Ebola virus cases occur in children: it is therefore crucial to evaluate vaccines in this population, particularly in very young children whose immune systems are still developing. -
Three immunization strategies are being tested in this study, in order to determine whether the vaccines are well tolerated and to measure the speed, intensity and duration of the immune system reactions generated by these vaccines against Ebola. In the event of a new epidemic, the study participants who received placebo can be immunized. -
The blood samples collected from the trial volunteers are repackaged in the laboratory. Ultimately, they will also be used to constitute a biobank, useful for future research. -
At a meeting of the PREVAC international consortium in Conakry for a progress update on the scientific and operational aspects of the trial, Éric D’Ortenzio, scientific coordinator of the trial in Guinea, Aurélie Wiedemann, immunologist, and Renaud Vatrinet, laboratory manager, discuss the schedule for shipping and analyzing the samples in the various countries of the consortium. -
Lansana Keita (right) is the first volunteer in the Mafèrinyah vaccine trial. A retired pineapple juice factory worker, he regularly visits the vaccination center to share his experience and assist new volunteers. Here he is talking with Éric D’Ortenzio. The first results of the study are expected in 2020. A hope for all populations hit by Ebola. -
Bernard Yaradouno, nurse, takes the tubes of blood drawn from the volunteers. They will be processed in the laboratory in order to measure the antibodies and will also be used to create a biobank which could be useful for future research. -
Consultation room in the Landréah vaccination center in Conakry. Vaccinations are according to the double-blind principle. Neither the nurse nor the candidate know what is being administered. It may be one of the two vaccines or a placebo. The injections are determined by software and prepared under pharmacy secrecy.
And yet, against a background of trauma and general distrust surrounding Ebola, the challenge facing Inserm and its partners in the PREVAC (Partnership for Research on Ebola VACcination) consortium has been considerable: launch a large-scale clinical trial in Africa to test the most promising vaccination strategies against this scourge which claimed almost 30 000 victims in 2014.
On the ground, one of the keys to success involves collaboration between the team of anthropologists from PREVAC and the "community champions", whose authority and legitimacy recognized by the local communities help to get the latter on board. In the neighborhoods, the PREVAC team, supported by the community champions, steps up the awareness-raising meetings in order to recruit volunteers.
For Sylvain Faye, anthropologist of the clinical trial, "there is no doubt that the realization that a vaccine trial is also a social process" is one of the major strengths of the project. 5 000 people, half of whom children, will ultimately be enrolled in the trial in the four participating countries (Guinea, Liberia, Mali and Sierra Leone).
One and a half years after the start of the operation, almost 1 000 people have already been enrolled in Guinea and 4 500 across the four countries. Each day, almost 70 volunteers are received in Guinea’s two vaccination centers, which are managed by the non-governmental organization Alima, partner of Inserm for the project. A plunge into the heart of PREVAC.
Find the report in issue 41 of Science&Santé magazine
Photo: © Inserm/Delapierre, Patrick
