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Researchers have made a breakthrough in developing a new immunization to combat a fatal virus that affects juvenile elephants.

The inoculation, produced by an global scientific group, is designed to prevent the serious disease caused by elephant endotheliotropic herpesvirus (EEHV), which is presently a leading cause of death in young Asian elephants.

In trials that involved adult elephants at the facility, the vaccine was found to be harmless and, crucially, to stimulate part of the body's defenses that helps fighting viruses.

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

It is anticipated that the outcome of this pioneering trial will pave the way to preventing the deaths of young elephants from the harmful condition caused by this virus.

Severe Consequences

EEHV has had a especially devastating impact in captive environments. At Chester Zoo alone, seven young elephants have died to it over the last decade. It has also been found in wild elephant herds and in some sanctuaries and care centers.

It causes a bleeding disorder - uncontrolled bleeding that can be fatal within 24 hours. It results in death in over eighty percent of cases in juvenile elephants.

Understanding the Threat

Why EEHV can be so lethal is still unknown. Many adult elephants carry the virus - apparently with no adverse effects on their health. But it is believed that young calves are especially vulnerable when they are being weaned, and when the protective defenses from the mother's milk decline.

At this phase, a calf's immune system is in a delicate state and it can become overwhelmed. "It may lead to extremely serious disease," a lead conservation scientist stated.

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

Vaccine Development

The research team, led by animal health experts, created the novel vaccine using a tried and tested "scaffold". Essentially, the core design of this vaccine is identical to one commonly employed to vaccinate elephants against a virus called cowpox.

The researchers seeded this vaccine structure with proteins from EEHV - harmless parts of the virus that the elephant's defense system might identify and respond to.

In a pioneering trial, the team tested the new vaccine in three fit, adult elephants at the zoo, then examined blood tests from the vaccinated animals.

Prof Steinbach commented that the results, published in a research publication, were "better than we had hoped for".

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

Future Steps

The subsequent phase for the scientists is to try the vaccine in more juvenile elephants, which are the animals most at risk to serious illness.

The present vaccination involves four shots to be given, so another aim is to determine if the equivalent protective dose can be given in a simpler way - possibly with fewer jabs.

The conservation scientist 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 get it to where it's needed."

Prof Steinbach added: "We think this is a major advancement, and not just solely for the elephants, but because it additionally shows that you can develop and use vaccines to assist threatened animals."