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Scientists have achieved a major advance in developing a novel immunization to prevent a deadly virus that targets young elephants.

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

In tests that included mature elephants at Chester Zoo, the vaccine was found to be safe and, importantly, to activate components of the body's defenses that assists in fighting viruses.

A lead scientist called this as "a landmark moment 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 harmful disease caused by this virus.

Severe Consequences

EEHV has had a particularly devastating effect in zoos. At Chester Zoo by itself, seven young elephants have died to it over the last decade. It has additionally been detected in wild elephant herds and in certain refuges and care centers.

It causes a bleeding disorder - unchecked hemorrhaging that can be deadly within a day. It results in death in more than 80% of cases in juvenile elephants.

Understanding the Threat

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 elephants are particularly vulnerable when they are being weaned, and when the immune-boosting defenses from the maternal nutrition decline.

At this phase, a young elephant's immune system is in a precarious balance and it can become overwhelmed. "It may lead to extremely serious disease," a lead conservation scientist explained.

"It impacts wild elephants, but we lack an exact number of how many fatalities in overall it has caused. For elephants in human care however, there have been more than 100 deaths."

Vaccine Development

The scientific group, led by animal health experts, developed the new vaccine using a tried and tested "framework". Basically, the core design of this vaccine is the same to one commonly employed to immunise elephants against a virus called a related virus.

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

In a world-first experiment, the team tested the new vaccine in three fit, adult elephants at the zoo, then analysed blood samples from the vaccinated animals.

Prof Steinbach stated 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 stimulate the production of T cells, that are vital to fighting virus attacks."

Future Steps

The subsequent phase for the scientists is to test the vaccine in younger elephants, which are the animals most vulnerable to serious illness.

The current vaccination requires multiple shots to be administered, so an additional objective is to work out if the equivalent protective amount can be provided in a more straightforward way - perhaps with fewer jabs.

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

Prof Steinbach added: "We think this is a major step forward, and not necessarily solely for the elephants, but because it also shows that you can design and apply vaccines to assist endangered species."