Johnson & Johnson (J&J) has begun a safety and immunogenicity clinical trial in Sierra Leone of a preventive Ebola vaccine regimen in development at its Janssen Pharmaceutical Companies. Trial recruitment is underway, and the first volunteers have received their initial vaccine dose. It is the first study conducted of Janssen’s Ebola prime-boost vaccine regimen in a West African country affected by the recent Ebola epidemic.

The new study, EBOVAC-Salone, will take place in Sierra Leone’s Kambia district, where some of the country’s most recent Ebola cases have been reported. The regimen being tested uses a combination of two vaccine components based on AdVac technology from Crucell Holland and MVA-BN technology from Bavarian Nordic. Study volunteers will first be given the AdVac dose to prime their immune system, and then the MVA-BN dose two months later to boost their immune response, with the goal of potentially strengthening and optimizing the duration of the immunity.

Since announcing its commitment to combat Ebola in October 2014, J&J has mobilized significant resources to advance the research and development of an Ebola vaccine regimen with the goal of addressing the urgent public health need of affected countries such as Sierra Leone. With that goal in mind, Janssen developed partnerships and consortia this year with other companies and research institutions, secured funding from European and U.S. public authorities, and launched multiple phase I and II studies in rapid succession across the U.S., Europe and Africa.

First-in-human phase I clinical studies of the prime-boost vaccine regimen began in the U.K. and U.S. in January, followed by several sites in Africa. In May, J&J presented promising preliminary data from the U.K. phase I study to the FDA. A phase II study, being carried out in the U.K. and France, started in July, and a second multisite phase II study will shortly commence in several West and East African countries in outside epidemic areas.