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Scientists have made a major advance in developing a novel vaccine to combat a fatal virus that targets juvenile elephants.

The vaccine, produced by an global scientific group, is designed to stop the severe disease caused by EEHV, which is presently a primary cause of death in juvenile Asian elephants.

In trials that included mature elephants at the facility, the vaccine was found to be safe and, importantly, to stimulate part of the body's defenses that assists in combating viruses.

Prof Falko Steinbach described this as "a pivotal step in our work to protect Asian elephants".

It is hoped that the result of this first-of-its-kind study will pave the way to averting the deaths of juvenile elephants from the dangerous condition caused by this virus.

Devastating Impact

EEHV has had a especially destructive effect in zoos. At Chester Zoo by itself, seven baby elephants have succumbed to it over the last decade. It has additionally been found in natural populations and in some refuges and care centers.

It causes a haemorrhagic disease - unchecked bleeding that can be deadly within 24 hours. It results in death in more than 80% of instances in juvenile elephants.

Understanding the Threat

Why EEHV can be so dangerous is remains unclear. Numerous adult elephants host the virus - apparently with no adverse effects on their well-being. But it is thought that young elephants are particularly susceptible when they are being weaned, and when the protective defenses from the maternal nutrition decrease.

At this phase, a young elephant's immune system is in a delicate state and it can become overpowered. "It may lead to really severe illness," a lead conservation scientist stated.

"It does affect elephants in nature, but we don't have an exact number of how many fatalities in total it has resulted in. For elephants in human care though, there have been more than 100 deaths."

Immunization Creation

The scientific group, led by veterinary scientists, created the new vaccine using a tried and tested "framework". Essentially, the basic structure of this vaccine is the same to one commonly employed to immunise elephants against a virus called cowpox.

The scientists seeded this immunization framework with components from EEHV - harmless parts of the virus that the elephant's defense system might recognise and respond to.

In a world-first trial, the team tested the novel vaccine in three fit, adult elephants at Chester Zoo, then examined blood samples from the vaccinated animals.

Prof Steinbach stated that the results, released in a research publication, were "better than we had hoped for".

"They showed, clearly that the vaccine was able to stimulate the production of immune cells, that are crucial to combating virus attacks."

Next Phases

The subsequent phase for the researchers is to try the vaccine in younger elephants, which are the animals most vulnerable to severe illness.

The current vaccination requires four shots to be given, so another aim is to determine if the equivalent effective dose can be given in a simpler way - possibly with fewer injections.

Dr Edwards clarified: "Ultimately we want to use this vaccine in the elephants that are in danger, so we need to make sure that we can get it to where it's needed."

The project lead added: "We believe this is a major step forward, and not necessarily only for the elephants, but because it also shows that you can design and use vaccines to help endangered species."