Efficacy of ebola vaccine to be assessed in large-scale clinical trial

By Kate Bass, B.Sc.Jan 23 2015

GlaxoSmithKline (GSK) announced today that they will soon be commencing the first large-scale clinical trial to assess the efficacy of an experimental ebola vaccine.

GSK is one of the largest vaccine producers in the world, supplying over 2 million vaccines every day. They have developed a broad portfolio of vaccines that help prevent illnesses such as diphtheria, tetanus, whooping cough, measles, mumps, rubella, hepatitis, rotavirus and human papilloma virus infections, bacterial meningitis and influenza.

GSK has been working with the National Institutes of Health to accelerate development of an ebola vaccine in response to the current epidemic. They have used a type of cold virus (adenovirus type 3) to deliver benign genetic material from the ebola virus and stimulate production of antibodies against the ebola virus, which in turn will afford protection against future contact with the virus responsible for the current Ebola outbreak in west Africa. The vaccine is soon to be evaluated in the first large-scale phase III trial.

Initial data from five small phase I clinical trials conducted in around 200 healthy volunteers in the UK, USA, Switzerland and Mali, show that the candidate vaccine has an acceptable safety profile and produces an immune response. The dose showing the best safety and immunological profiles was chosen for further investigation in a large phase III clinical trial.

The first batch of 300 vials of the ebola vaccine is expected to arrive in Liberia (one of the countries worst hit by ebola) later today. The trial will recruit up to 30,000 people, including healthcare workers, to receive either the ebola vaccine or a control vaccine and be monitored for acquired ebola immunity. This trial will begin in Liberia in the coming weeks, subject to regulatory approval.

Dr Moncef Slaoui, Chairman of Global Vaccines at GSK, said:

The initial phase I data we have seen are encouraging and give us confidence to progress to the next phases of clinical testing which will involve the vaccination of thousands of volunteers, including frontline healthcare workers. If the candidate vaccine is able to protect these people, as we hope it will, it could significantly contribute to efforts to bring this epidemic under control and prevent future outbreaks.

Although, this is a big step forward, it is important to remember that the ebola vaccine is still in development and any potential future use in mass vaccination campaigns will depend on whether stakeholders, such as the World Health Organisation, and medical regulators, are satisfied that the vaccine provides adequate protection against ebola without causing significant side effects.

GSK is working closely with the World Health Organization and Centers for Disease Control and Prevention on the design of trials in other affected countries and also plans to begin large phase II safety trials in non-affected west African countries.