World’s first pilot study to fight deadly elephant virus

Elephant endotheliotropic herpesvirus (EEHV) is a major threat to the long-term survival of the Asian elephant, of which just 40,000 now remain. Reports of wild elephant fatalities at the hands of the disease are sadly on the rise in India, Nepal, Myanmar and Thailand. More cases have been recorded in five further countries across its native range, as well as in zoo conservation breeding programmes worldwide.

Asian elephants are listed as Endangered on the International Union for the Conservation of Nature’s (IUCN) Red List of Threatened Species. A vaccine that can protect this amazing species is widely viewed by conservationists as the best hope for tackling the virus.

Our experts at the zoo have been researching EEHV for many years along with our partners, and thanks to your support through our Never Forget fundraising campaign, we have made great progress in tackling this deadly virus. In 2019 we were able to develop innovative treatments which saved a young elephant in our group, Indali Hi-Way. Now, thanks to your continued support, we have developed the first vaccine of its kind to ever enter a pilot study, anywhere in the world.

Pioneering pilot study

This ground-breaking new vaccination has been developed as a result of a long term collaboration led by our teams and scientists at the University of Surrey. Our elephant care experts are leading the first vaccine pilot study, supported by a host of other major conservation zoos in the UK and Ireland, including Dublin Zoo, Whipsnade Zoo, Blackpool Zoo and Woburn Safari Park.

Mike Jordan, our Director of Animals and Plants, said: “The only long-term solution to beating EEHV is to find a vaccine. Without zoos caring for the species it would be almost impossible to achieve that but, thankfully, we’re now making remarkable progress. The global conservation community is today a step closer to finding a viable vaccine to save Asian elephants from this deadly disease.”

Our healthy 20-year old male elephant is the first to participate in the pilot study and from early tests the vaccine appears to stimulate an immune response.

Without the expertise and opportunities for close contact offered by zoos caring for the species, experts say it would be “almost impossible” to develop a vaccine, which, if successful, could help to prevent the extinction of the species.

Dr Tanja Maehr, Lead Researcher at the University of Surrey and Chester Zoo Conservation Fellow, added: “This is an important moment in our research. Now that we have entered a pilot study stage there is real optimism we can find a safe vaccine that works. We are, however, not getting ahead of ourselves. While this is a significant step in right direction, and the initial signs are positive, these are still early days.

“The initial results from the trials are encouraging, not least that the vaccine appears to stimulate an immune response. This is a small step for vaccines and a large step for the world’s elephants.”

“It’ll be several months until the first stage of our work to select the best candidate vaccine and determine optimal dosages and frequencies is complete. Then, if successful, further trials in zoos and in the field will need to take place to fully ascertain its efficacy.”

 Keep an eye out for more updates over the coming months!

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Read our latest feature on vaccines to delve in deeper to the science behind developing this vaccine.