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Researchers have achieved a major advance in developing a new immunization to combat a deadly virus that targets young elephants.

The inoculation, produced by an international research team, aims to prevent the severe illness caused by EEHV, which is presently a leading cause of death in young Asian elephants.

In trials that involved adult elephants at Chester Zoo, the vaccine was found to be safe and, crucially, to activate components of the body's defenses that helps combating viruses.

A lead scientist described this as "a pivotal step in our work to safeguard Asian elephants".

It is hoped that the outcome of this first-of-its-kind trial will open the door to averting the fatalities of juvenile elephants from the dangerous disease caused by this virus.

Severe Consequences

EEHV has had a particularly devastating impact in zoos. At Chester Zoo alone, multiple baby elephants have died to it over the last decade. It has also been found in natural populations and in some refuges and elephant orphanages.

It causes a haemorrhagic disease - uncontrolled 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 unclear. Numerous mature elephants host the virus - seemingly with no negative impact on their well-being. But it is believed that juvenile calves are particularly vulnerable when they are being weaned, and when the immune-boosting antibodies from the mother's milk decline.

At this stage, a young elephant's natural defenses is in a precarious state and it can become overwhelmed. "It may lead to extremely serious disease," Dr Katie Edwards stated.

"It does affect elephants in nature, but we don't have an precise count of how many fatalities in overall it has resulted in. For elephants in captivity though, there have been over a hundred deaths."

Immunization Creation

The research team, headed by veterinary scientists, created the new vaccine using a tried and tested "framework". Essentially, 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 parts of the virus that the elephant's immune system might recognise and respond to.

In a pioneering experiment, the team tested the novel vaccine in several healthy, adult elephants at Chester Zoo, then analysed blood samples from the innoculated animals.

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

"The results demonstrated, clearly that the vaccine was able to activate the production of T cells, that are vital to combating virus attacks."

Next Phases

The next step for the researchers is to try the vaccine in more juvenile elephants, which are the creatures most vulnerable to severe disease.

The present vaccination involves four shots to be administered, so another aim is to work out if the equivalent protective dose can be given in a simpler way - perhaps with less jabs.

The conservation scientist clarified: "In the end we want to use this vaccine in the elephants that are at risk, so we need to make sure that we can get it to where it's needed."

The project lead continued: "We think this is a significant step forward, and not just only for the elephants, but because it additionally demonstrates that you can develop and use vaccines to assist threatened animals."