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

The inoculation, developed by an global research team, is designed to prevent the severe illness caused by elephant endotheliotropic herpesvirus (EEHV), which is currently a primary cause of death in young Asian elephants.

In trials that involved adult elephants at Chester Zoo, the vaccine was found to be safe and, importantly, to stimulate components of the body's defenses 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 pave the way to preventing the fatalities of juvenile elephants from the dangerous disease caused by this virus.

Devastating Impact

EEHV has had a particularly destructive impact in zoos. At one facility by itself, seven young elephants have died to it over the past ten years. It has also been found in natural populations and in some sanctuaries and care centers.

It causes a haemorrhagic disease - uncontrolled bleeding that can be fatal within 24 hours. It leads to death in over eighty percent of instances in juvenile elephants.

Comprehending the Danger

Why EEHV can be so lethal is still unclear. Many mature elephants carry the virus - seemingly with no negative impact on their health. But it is believed that juvenile calves are especially susceptible when they are being weaned, and when the protective defenses from the mother's milk decrease.

At this phase, a young elephant's immune system is in a delicate balance and it can become overwhelmed. "It can cause really severe illness," a lead conservation scientist stated.

"It impacts wild elephants, but we don't have an exact number of how many deaths in overall it has resulted in. For elephants in captivity however, there have been more than 100 deaths."

Immunization Creation

The scientific group, headed by veterinary scientists, developed the novel vaccine using a proven "scaffold". Basically, the basic structure of this vaccine is identical to one routinely used to immunise elephants against a virus called a related virus.

The scientists seeded this immunization framework with components from EEHV - harmless bits 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 healthy, adult elephants at the zoo, then analysed blood tests from the vaccinated animals.

The lead researcher commented that the results, published in a research publication, were "better than we had hoped for".

"They showed, clearly that the vaccine was able to activate the generation of T cells, that are crucial to combating virus attacks."

Next Phases

The subsequent phase for the researchers is to try the vaccine in more juvenile elephants, which are the animals most vulnerable to serious disease.

The current vaccination requires multiple injections to be given, so another aim is to work out if the same protective dose can be provided in a more straightforward way - perhaps with fewer jabs.

The conservation scientist explained: "Ultimately 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 believe this is a significant advancement, and not necessarily only for the elephants, but because it additionally demonstrates that you can design and apply vaccines to help threatened animals."