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Researchers have made a breakthrough in developing a new immunization to prevent a deadly virus that targets young elephants.

The inoculation, developed by an international research team, aims to stop the serious illness caused by EEHV, which is currently a primary cause of death in juvenile Asian elephants.

In trials that included adult elephants at Chester Zoo, the vaccine was found to be harmless and, crucially, to activate part of the immune system that assists in combating viruses.

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

It is hoped that the outcome of this pioneering study will open the door to preventing the fatalities of juvenile elephants from the harmful condition caused by this virus.

Severe Consequences

EEHV has had a particularly destructive impact in captive environments. At Chester Zoo by itself, seven baby elephants have succumbed to it over the past ten years. It has also been detected in natural populations and in certain sanctuaries and elephant orphanages.

It causes a bleeding disorder - unchecked bleeding that can be fatal within 24 hours. 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. Numerous mature elephants host the virus - apparently with no adverse effects on their well-being. But it is believed that juvenile elephants are particularly susceptible when they are being transitioned from milk, and when the protective defenses from the mother's milk decrease.

At this stage, a young elephant's natural defenses is in a precarious balance and it can become overpowered. "It can cause extremely serious illness," Dr Katie Edwards explained.

"It impacts elephants in nature, but we lack an precise count of how many fatalities in total it has caused. For elephants in human care however, there have been more than 100 deaths."

Immunization Creation

The research team, led by veterinary scientists, developed the new vaccine using a proven "scaffold". Essentially, the core design of this vaccine is identical to one commonly employed to immunise elephants against a virus called cowpox.

The scientists incorporated this vaccine structure with proteins from EEHV - non-infectious bits of the virus that the elephant's immune system might identify and respond to.

In a pioneering experiment, the team tested the novel vaccine in three fit, mature elephants at the zoo, then analysed blood tests from the innoculated animals.

The lead researcher stated that the results, released in a scientific journal, were "better than we had hoped for".

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

Next Phases

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

The current vaccination requires multiple shots to be administered, so an additional objective is to determine if the equivalent effective amount can be provided in a simpler way - possibly with less injections.

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

Prof Steinbach 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."