An independent body of international experts – the Data and Safety Monitoring Board – has advised that a trial for the experimental Guinea phase 3 Ebola vaccine (VSV-EBOV, Merck, Sharp & Dohme) move forward as the vaccine is is showing promising results against the potentially-deadly illness.
While the vaccine up to now shows 100% efficacy in individuals, more conclusive evidence is needed on its capacity to protect populations through herd immunity, according to a press release from WHO. Preliminary results from analyses of these interim data are published today in the The Lancet.
To that end, the Guinean national regulatory authority and ethics review committee have approved continuation of the trial.
The Guinea vaccination trial began in affected communities on March 23, 2015 to evaluate the efficacy, effectiveness and safety of a single dose of the vaccine VSV-EBOV by using a ring vaccination strategy. To date, more than 4,000 close contacts of almost 100 Ebola patients, have participated in the trial.
The trial stopped randomization earlier this week to allow for all people at risk to receive the vaccine immediately, and to minimize the time necessary to gather more conclusive evidence needed for eventual licensure of the product.
Until now, 50% of the rings were vaccinated three weeks after the identification of an infected patient to provide a term of comparison with rings that were vaccinated immediately. This now stops. In addition, the trial will now include 13- to 17-year-old and possibly 6- to 12-year-old children on the basis of new evidence of the vaccine’s safety.
In addition to ring vaccination, the trials are being conducted on frontline wokers as well.
The trial is being implemented by the Guinean authorities, WHO, Médecins sans Frontières (MSF) and the Norwegian Institute of Public Health, with support from a broad partnership of international and national organizations.
“This record-breaking work marks a turning point in the history of health R&D,” Assistant Director-General Marie-Paule Kieny, who leads the Ebola Research and Development effort at WHO, said in a press release. “We now know that the urgency of saving lives can accelerate research and development (R&D). We will harness this positive experience to develop a global R&D preparedness framework so that if another major disease outbreak ever happens again, for any disease, the world can act quickly and efficiently to develop and use medical tools and prevent a large-scale tragedy.”