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Scientists have achieved a major advance in creating a new immunization to combat a fatal virus that affects juvenile elephants.

The vaccine, produced by an global scientific group, is designed to prevent the severe illness caused by EEHV, which is currently 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 activate part of the body's defenses that helps fighting viruses.

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

It is hoped that the result of this pioneering study will pave the way to preventing the deaths of juvenile elephants from the harmful condition caused by this virus.

Severe Consequences

EEHV has had a particularly devastating impact in zoos. At Chester Zoo by itself, multiple young elephants have succumbed to it over the last decade. It has also been detected in wild elephant herds and in some refuges and elephant orphanages.

It causes a bleeding disorder - unchecked bleeding that can be deadly within a day. It results in death in more than 80% of cases in juvenile elephants.

Understanding the Threat

Why EEHV can be so dangerous is remains unknown. Many adult elephants host the virus - seemingly with no negative impact on their health. But it is thought that young calves are especially vulnerable when they are being weaned, and when the protective defenses from the mother's milk decrease.

At this stage, a calf's immune system is in a precarious state and it can become overpowered. "It may lead to extremely serious illness," a lead conservation scientist explained.

"It does affect elephants in nature, but we don't have an exact number of how many fatalities in overall it has caused. For elephants in human care however, there have been over a hundred deaths."

Vaccine Development

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

The researchers 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 experiment, the team tested the novel vaccine in several fit, mature elephants at the zoo, then examined blood samples from the innoculated animals.

Prof Steinbach commented that the findings, released in a scientific journal, were "more successful than anticipated".

"They showed, clearly that the vaccine was able to stimulate the generation of T cells, that are vital to fighting virus attacks."

Future Steps

The subsequent phase for the scientists is to test the vaccine in more juvenile elephants, which are the animals most at risk to severe disease.

The present vaccination involves four injections to be given, so another aim is to determine if the same protective amount can be given in a simpler way - perhaps with less jabs.

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

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