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Scientists have made a major advance in developing a novel immunization to prevent a deadly virus that targets juvenile elephants.

The vaccine, produced by an global scientific group, is designed to prevent the serious illness caused by EEHV, which is currently a leading cause of death in juvenile Asian elephants.

In tests that involved adult elephants at the facility, the vaccine was found to be safe and, importantly, to stimulate components of the body's defenses that helps combating viruses.

A lead scientist described this as "a pivotal step in our work to protect Asian elephants".

It is hoped that the outcome of this pioneering study will open the door to averting the deaths of juvenile elephants from the dangerous condition caused by this virus.

Severe Consequences

EEHV has had a especially destructive effect in zoos. At Chester Zoo by itself, multiple young elephants have died to it over the last decade. It has also been detected in natural populations and in certain sanctuaries and elephant orphanages.

It causes a haemorrhagic disease - unchecked hemorrhaging that can be deadly within 24 hours. It leads to death in more than 80% of cases in juvenile elephants.

Understanding the Threat

Why EEHV can be so lethal is remains unknown. Many mature elephants host the virus - apparently with no adverse effects on their health. But it is thought that juvenile calves are especially susceptible when they are being weaned, and when the protective defenses from the mother's milk decrease.

At this phase, a young elephant's natural defenses is in a precarious balance and it can become overpowered. "It can cause really severe disease," a lead conservation scientist explained.

"It does affect wild elephants, but we don't have an precise count of how many deaths in overall it has resulted in. For elephants in captivity however, there have been more than 100 deaths."

Vaccine Development

The scientific group, headed by animal health experts, developed the novel vaccine using a tried and tested "framework". Basically, the core design of this vaccine is identical to one routinely used to vaccinate elephants against a virus called a related virus.

The scientists seeded this vaccine structure with components from EEHV - harmless bits of the virus that the animal's defense system might recognise and react against.

In a pioneering trial, the team tested the new vaccine in several fit, adult elephants at the zoo, then examined blood samples from the vaccinated animals.

Prof Steinbach stated that the results, published in a scientific journal, were "more successful than anticipated".

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

Next Phases

The subsequent phase for the scientists is to test the vaccine in younger elephants, which are the creatures most at risk to severe illness.

The current vaccination involves multiple shots to be given, so an additional objective is to determine if the equivalent effective amount can be given in a more straightforward way - possibly with fewer jabs.

Dr Edwards clarified: "In the end we aim to use this vaccine in the elephants that are in danger, so we need to ensure that we can get it to where it's necessary."

Prof Steinbach added: "We believe this is a major step forward, and not necessarily solely for the elephants, but because it additionally shows that you can design and apply vaccines to help threatened animals."