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

The vaccine, developed by an global scientific group, aims to prevent the serious illness caused by EEHV, which is currently a leading cause of death in juvenile Asian elephants.

In trials that involved adult elephants at Chester Zoo, the vaccine was found to be harmless and, crucially, to stimulate part of the body's defenses that assists in fighting 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 young elephants from the dangerous condition caused by this virus.

Devastating Impact

EEHV has had a especially destructive effect in captive environments. At one facility alone, multiple young elephants have succumbed to it over the last decade. 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 leads to death in more than 80% of instances in juvenile elephants.

Understanding the Threat

Why EEHV can be so lethal is still unknown. Many adult elephants host the virus - seemingly with no adverse effects on their well-being. But it is thought that young elephants are particularly vulnerable when they are being transitioned from milk, and when the protective antibodies from the mother's milk decline.

At this stage, a young elephant's immune system is in a precarious balance and it can become overpowered. "It may lead to extremely serious illness," Dr Katie Edwards explained.

"It does affect elephants in nature, but we don't have an exact number of how many fatalities in total it has caused. For elephants in captivity however, there have been more than 100 deaths."

Immunization Creation

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

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

In a pioneering trial, the team evaluated the new vaccine in three healthy, mature elephants at Chester Zoo, then examined blood samples from the vaccinated animals.

The lead researcher commented that the findings, released in a research publication, were "more successful than anticipated".

"They showed, unequivocally that the vaccine was able to activate the production of immune cells, that are vital to combating viral infections."

Future Steps

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

The present vaccination requires multiple shots to be administered, so another aim is to determine if the equivalent effective dose can be given in a simpler way - possibly with less jabs.

The conservation scientist explained: "Ultimately we aim to use this vaccine in the elephants that are in danger, so we want to make sure that we can get it to where it's necessary."

The project lead continued: "We think this is a major step forward, and not necessarily only for the elephants, but because it also demonstrates that you can develop and apply vaccines to help endangered species."