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Scientists have achieved a breakthrough in developing a new vaccine to combat a deadly virus that affects young elephants.

The inoculation, developed by an global research team, aims to stop the serious illness caused by elephant endotheliotropic herpesvirus (EEHV), which is currently a leading cause of death in juvenile Asian elephants.

In tests that included mature elephants at Chester Zoo, the vaccine was found to be harmless and, importantly, to stimulate part of the immune system that assists in combating viruses.

Prof Falko Steinbach described this as "a pivotal step in our efforts to protect Asian elephants".

It is anticipated that the outcome of this first-of-its-kind 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 devastating effect in zoos. At Chester Zoo alone, seven young elephants have died to it over the past ten years. It has also been found in wild elephant herds and in some refuges and elephant orphanages.

It causes a haemorrhagic disease - uncontrolled hemorrhaging that can be fatal within a day. It results in death in over eighty percent of instances in young elephants.

Comprehending the Danger

Why EEHV can be so lethal is still unknown. Numerous mature elephants host the virus - apparently with no negative impact on their well-being. But it is believed that young calves are particularly vulnerable when they are being weaned, and when the immune-boosting antibodies from the maternal nutrition decrease.

At this stage, a calf's immune system is in a precarious balance and it can become overwhelmed. "It may lead to really severe illness," a lead conservation scientist stated.

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

Vaccine Development

The scientific group, headed by animal health experts, created the novel vaccine using a proven "scaffold". Basically, the core design of this vaccine is identical to one commonly employed to immunise elephants against a virus called a related virus.

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

In a world-first experiment, the team evaluated the new vaccine in three fit, mature elephants at the zoo, then examined blood tests from the vaccinated animals.

The lead researcher commented that the findings, published in a scientific journal, were "more successful than anticipated".

"The results demonstrated, clearly that the vaccine was effective to stimulate the production of immune cells, that are crucial to combating viral infections."

Next Phases

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

The current vaccination involves multiple injections to be administered, so another aim is to determine if the equivalent effective dose can be given in a more straightforward way - possibly with less jabs.

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

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