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Scientists have made a breakthrough in developing a novel immunization to combat a fatal virus that targets juvenile elephants.

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

In trials that included mature elephants at Chester Zoo, the vaccine was found to be harmless and, crucially, to stimulate part of the immune system that helps fighting viruses.

A lead scientist described this as "a landmark moment in our efforts to safeguard Asian elephants".

It is hoped that the result of this pioneering study will open the door to preventing the fatalities of young elephants from the dangerous disease caused by this virus.

Severe Consequences

EEHV has had a especially devastating effect in captive environments. 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 elephant orphanages.

It causes a haemorrhagic disease - uncontrolled hemorrhaging that can be fatal within a day. It leads to death in more than 80% of instances in young elephants.

Comprehending the Danger

Why EEHV can be so dangerous is remains unknown. Many mature elephants carry the virus - apparently with no adverse effects on their well-being. But it is believed that young elephants are particularly susceptible when they are being weaned, and when the immune-boosting defenses from the mother's milk decline.

At this stage, a young elephant's immune system is in a delicate state and it can become overpowered. "It can cause really severe illness," Dr Katie Edwards explained.

"It impacts wild elephants, but we don't have an precise count of how many fatalities in overall it has resulted in. For elephants in captivity though, there have been over a hundred deaths."

Vaccine Development

The scientific group, headed by veterinary scientists, developed the novel vaccine using a tried and tested "framework". Basically, the core design of this vaccine is the same to one commonly employed to vaccinate elephants against a virus called cowpox.

The researchers incorporated this immunization framework with proteins from EEHV - harmless parts of the virus that the animal's immune system might identify and react against.

In a pioneering experiment, the team tested the new vaccine in several fit, adult elephants at Chester Zoo, then examined blood samples from the innoculated animals.

Prof Steinbach commented that the results, published in a research publication, were "more successful than anticipated".

"They showed, unequivocally that the vaccine was able to stimulate the generation of T cells, that are vital to fighting viral infections."

Future Steps

The subsequent phase for the researchers is to test the vaccine in more juvenile elephants, which are the animals most vulnerable to serious disease.

The current immunization involves four injections to be administered, so an additional objective is to determine if the equivalent protective amount can be provided in a more straightforward way - perhaps with fewer jabs.

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

Prof Steinbach added: "We believe this is a significant step forward, and not just solely for the elephants, but because it also demonstrates that you can develop and apply vaccines to assist endangered species."