An interim review published today in the medical journal The Lancet indicates very promising results for one of the Ebola vaccine candidates. The interim review states that the efficacy of the vaccine is 100 percent. The trial of the so-called rVSV-EBOV vaccine has been led by the World Health Organization (WHO), Doctors Without Borders/Médecins Sans Frontières (MSF), the Norwegian Institute of Public Health, and the Guinean health authorities. It started in March 2015 in Guinea and focused on “rings” of people around the infected patients as well as on frontline workers at risk of contracting the disease.
MSF is heavily involved in the trial by administering the vaccine to 1,200 frontline workers in Guinea, including doctors, nurses, paramedics, laboratory staff, cleaning staff, and burial teams. Dr. Bertrand Draguez, who has been spearheading the MSF platform on experimental tools for Ebola, tells us what that means for the fight against the disease.
What does the preliminary data tell us?
The current data basically tells us that the vaccine works to protect people against Ebola. Even if the sample size is quite small and more research and analysis is needed, the enormity of the public health emergency should lead us to continue using this vaccine right now to protect those who might get exposed to the disease: contacts of infected patients and frontline workers.
How exciting are these preliminary results?
For the first time ever, we received evidence of efficacy of a vaccine that will help fighting Ebola. Too many people have been dying from this extremely deadly disease, and it has been very frustrating for health care workers to feel so powerless against it. More data is needed to tell us how efficacious this preventive tool actually is, but this is a unique breakthrough.
For example, it is not clear how soon protection kicks in and how long it lasts. All this needs to be determined by more research and analysis.
What does this mean in the fight against Ebola?
The current pattern of the epidemic—which is sporadic, with relatively small chains of transmissions popping up here and there—means that all the components of the fight against the disease need to be continued. This includes Ebola case management, isolation, community outreach, safe burials, health promotion, psycho-social support, and contact tracing.
But, of course, adding a preventive tool in the mix will accelerate the break-up of transmission chains by targeting people who have been in contact with infected patients, as well as frontline workers.
How can this new tool be best used?
Now that we know that the vaccine works, people who need it most should get it as soon as possible to break the existing chains of transmission. Replication of a targeted approach focusing on those most at risk of infection should therefore happen immediately and we urge governments in affected countries to start using this vaccine as soon as they can within the framework of the existing trial.
Should a mass vaccination campaign happen in all countries affected?
At the moment, the epidemic is quite localized in a few hotspots across the affected region. This kind of pattern means that it would make much more sense to focus our energy and resources in vaccinating people around infected patients and among frontline workers. They are the people most at risk of contracting the disease and should therefore be targeted as a matter of urgency.
How was MSF involved in the trial?
It is rare that MSF gets involved in clinical trials, but faced with the enormity of the crisis and our unique position on the frontline of the fight against Ebola, we took the decision to take part. In Guinea we have already vaccinated 1,200 frontline workers in this first phase of the trial. Now that the preliminary efficacy results are known, MSF is determined to expand on this and encourage and contribute to similar trials in Sierra Leone and Liberia.
Is this going to change MSF’s response in the affected countries?
These results are promising and we should definitely make this vaccine available to at-risk groups as soon as possible. But it is also of crucial importance to keep working on all the pillars of an Ebola response including contact tracing, health promotion, and isolation of infected patients.