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Scientists have made a major advance in creating a novel immunization to prevent a fatal virus that affects young elephants.

The inoculation, produced by an international scientific group, aims to stop the severe illness caused by elephant endotheliotropic herpesvirus (EEHV), which is presently a primary cause of death in juvenile Asian elephants.

In tests that included mature elephants at the facility, the vaccine was found to be harmless and, importantly, to activate components of the immune system that assists in combating viruses.

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

It is hoped that the outcome of this pioneering trial will pave the way to averting the deaths of juvenile elephants from the harmful condition caused by this virus.

Devastating Impact

EEHV has had a particularly devastating impact in captive environments. At one facility alone, seven baby elephants have succumbed to it over the last decade. It has also been detected in wild elephant herds and in some sanctuaries and elephant orphanages.

It causes a haemorrhagic disease - uncontrolled bleeding that can be fatal within a day. It leads to death in over eighty percent of instances in juvenile elephants.

Comprehending the Danger

Why EEHV can be so lethal is remains unknown. Many mature elephants host the virus - apparently with no negative impact on their health. But it is thought that young calves are especially vulnerable when they are being transitioned from milk, and when the immune-boosting defenses from the mother's milk decrease.

At this phase, a calf's natural defenses is in a delicate state and it can become overwhelmed. "It can cause really severe disease," a lead conservation scientist explained.

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

Immunization Creation

The scientific group, led by animal health experts, created the new vaccine using a tried and tested "scaffold". Essentially, the basic structure of this vaccine is identical to one routinely used to immunise elephants against a virus called a related virus.

The researchers seeded this vaccine structure with components from EEHV - non-infectious bits of the virus that the elephant's defense system might recognise and respond to.

In a pioneering trial, the team evaluated the novel vaccine in three fit, mature elephants at Chester Zoo, then examined blood tests from the vaccinated animals.

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

"The results demonstrated, clearly that the vaccine was effective to activate the production of T cells, that are vital to fighting viral infections."

Next Phases

The next step for the scientists is to test the vaccine in more juvenile elephants, which are the animals most at risk to serious illness.

The current vaccination involves multiple injections to be administered, so another aim is to work out if the same protective dose can be provided in a more straightforward way - possibly with less injections.

The conservation scientist explained: "In the end we aim to use this vaccine in the elephants that are at risk, so we want to ensure that we can deliver it to where it's needed."

Prof Steinbach added: "We think this is a significant step forward, and not just only for the elephants, but because it additionally demonstrates that you can develop and apply vaccines to help threatened animals."