A new intramuscular vaccine has been developed at the US National Institute of Allergy and Infectious Diseases (NIAID) and Okairos, a biotechnology company acquired by GlaxoSmithKline. Following the first human trial of this experimental vaccine against Ebola virus disease (EVD), scientists at NIAID have described it as ‘promising’. Their research was published in the New England Journal of Medicine.

Ebola Vaccine

Success in Early-Stage Clinical Trial

According to a BBC report, the 20 healthy volunteers who received the vaccine in Phase 1 of a clinical trial did not report any serious side effects and all produced antibodies within four weeks. The volunteers ages 18 to 50 were divided into two groups, one receiving a higher dose of the vaccine than the other. It was found that:

  • The group that received the higher dose showed a stronger antibody response
  • Seven volunteers in the high dose group and two in the lose dose one produced T-cell immune responses, which could be significant in protection against Ebola viruses

The trial which began in September in Bethesda, Maryland, will continue for 48 weeks.

The vaccine uses a chimpanzee cold virus which has been genetically modified to hold a non-infectious Ebola protein on its surface. It carries genetic material from two Ebola strains – Zaire, which is responsible for the current outbreak in West Africa, and Sudan. As it has no virus, it cannot cause the disease.

The BBC reports that up to 23 November, 5.689 people have died of EVD in six countries – Liberia, Guinea, Sierra Leone, Nigeria, the United States and Mali. In the absence of an approved vaccine or treatments, the management of this deadly infectious disease has been limited to palliative care and measures to prevent transmission.

Ebola Research – Expedited Efforts

Since the Ebola outbreak in March, a range of potential treatments including blood products, drug therapies, and immunoassay are under evaluation. WHO has launched urgent initiatives to encourage diagnostic innovation and speed up the delivery of better and faster tests to the affected countries.

In addition to the vaccine developed at NIAID, another vaccine developed by the Public Health Agency of Canada in Winnepeg is undergoing human safety testing. According to a report in Time, Canada has already donated 800 vials of this vaccine to WHO.