Fast-tracked Ebola vaccine to enter trials

A potential vaccine against the Zaire species of Ebola, which has currently claimed 1,550 lives in West Africa, is to be tested on healthy patients in the UK and US. The candidate vaccine has been fast-tracked by an international consortium and will be tested on 60 healthy volunteers at the University of Oxford’s Jenner Institute once ethical and regulatory approval is granted. The safety trial will run alongside a similar trial in the US, and if volunteers show a good response, it will – subject to approval – be rolled out to a further 40 volunteers in an MRC Unit in the Gambia, and another 40 in Mali. The vaccine is based on an attenuated strain of chimpanzee cold virus called chimp adenovirus type 3 (ChAd3), which acts as a carrier to deliver benign genetic material derived from the Zaire species of the virus. The vaccine allows the recipient’s cells to express a protein which prompts an immune response, and cannot cause an inoculated person to become infected with Ebola. Preclinical trials at the US National Institutes of Health (NIH) in non-human primates have shown promising results, and the next stage is to test the vaccine in a small groups of healthy volunteers. It is hoped that phase 1 trials will be completed by the end of the year, after which the vaccine could be fast-tracked if safe. Professor Adrian Hill, Director of the Jenner Institute, who is leading the study said: "The tragic events unfolding in Africa demand an urgent response. In recent years, similar investigational vaccines have safely immunised infants and adults against a range of diseases including malaria, HIV and Hepatitis C. We, and all our partners on this project, are optimistic that this candidate vaccine may prove useful against Ebola." More information: Genus Ebolavirus is 1 of 3 members of the Filoviridae family (filovirus), along with genus Marburgvirus and genus Cuevavirus. Genus Ebolavirus comprises 5 distinct species:

• Bundibugyo ebolavirus (BDBV)
• Zaire ebolavirus (EBOV)
• Reston ebolavirus (RESTV)
• Sudan ebolavirus (SUDV)
• Taï Forest ebolavirus (TAFV).

• Ebola virus disease (EVD), is a severe, often fatal illness in humans, where the fatality rate can reach 90%.
• In the current outbreak, there have been over 3,000 confirmed cases, although the figure is likely to be higher as many cases are unregistered. Fatality rate stands at 55% (1,550 deaths).
• The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission via bodily fluids.
• Fruit bats of the Pteropodidae family are considered to be the natural host of the Ebola virus. Humans and primates are considered to be accidental hosts.
• Ebola first appeared in 1976 in 2 simultaneous outbreaks, in Nzara, Sudan, and in Yambuku, Democratic Republic of Congo. The latter was in a village situated near the Ebola River, from which the disease takes its name.
• EVD outbreaks occur primarily in remote villages in Central and West Africa, near tropical rainforests.
• No specific treatment or vaccine is available for use in people or animals.