Swissmedic, the Swiss regulatory authority for therapeutic products has approved an application for a clinical trial with an experimental Ebola vaccine at the Lausanne University Hospital.

The trial will be conducted among 120 volunteer participants with support from the U.N. World Health Organization,Swissmedic said.

The experimental vaccine is to be initially administered on healthy volunteers who will be sent as medical staff to fight the Ebola epidemic in West Africa.

In a statement, the Bern-based Swiss government agency said the trial continues a series that began in the United States, Britain and Mali, using a vaccine based on a genetically modified chimpanzee adenovirus.

There are no proven drugs or vaccines for Ebola, mainly because the disease is so rare it's been hard to attract research funding.

The World Health Organization (WHO) has welcomed the approval by Swissmedic for a trial with an experimental Ebola vaccine at the Lausanne University Hospital (CHUV). This marks the latest step towards bringing safe and effective Ebola vaccines for testing and implementation as quickly as possible.

Approval means that the vaccine can be used on approximately 120 individuals in Lausanne. The trial, which is receiving support from WHO, is the latest in a series of trials that are ongoing in Mali, the United Kingdom, and the United States.

The vaccine is based on a genetically modified chimpanzee adenovirus ("ChAd-Ebola"; Chimpanzee-Adenovirus chAD3-ZEBOV). The trial will test the safety of the vaccine and its capacity to induce an immune response. Results from the CHUV trial will together with the results of other centres involved provide the basis for planning subsequent trials involving several thousand participants, and for choosing vaccine dose-level for efficacy trials.

Developed by the US National Institute of Allergy and Infectious Diseases (NIAID) and pharmaceutical company GlaxoSmithKline, the vaccine consists of a virus that is rendered harmless and used as genetic carrier for one Ebola protein. The application, submitted at the end of September 2014, was handled as a priority, given the dimensions of the Ebola epidemic in  West Africa.