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Researchers have made a major advance in creating a novel vaccine to prevent a fatal virus that targets young elephants.

The vaccine, developed by an international scientific group, aims to stop the serious illness caused by elephant endotheliotropic herpesvirus (EEHV), which is currently a primary cause of death in juvenile Asian elephants.

In tests that involved adult elephants at the facility, the vaccine was found to be harmless and, crucially, to activate part of the immune system that assists in combating viruses.

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

It is anticipated that the outcome of this pioneering study will open the door to averting the fatalities of juvenile elephants from the harmful disease caused by this virus.

Devastating Impact

EEHV has had a especially devastating effect in captive environments. At Chester Zoo alone, seven young elephants have succumbed to it over the past ten years. It has additionally been found in wild elephant herds and in certain sanctuaries and care centers.

It causes a bleeding disorder - unchecked hemorrhaging that can be deadly within 24 hours. It results in death in more than 80% of cases in juvenile elephants.

Understanding the Threat

Why EEHV can be so lethal is remains unclear. Many adult elephants host the virus - apparently with no adverse effects on their health. But it is thought that juvenile elephants are especially susceptible when they are being transitioned from milk, and when the protective defenses from the maternal nutrition decline.

At this stage, a young elephant's immune system is in a delicate state and it can become overwhelmed. "It can cause really severe illness," Dr Katie Edwards stated.

"It does affect elephants in nature, but we lack an exact number of how many fatalities in overall it has caused. For elephants in captivity however, there have been more than 100 deaths."

Vaccine Development

The scientific group, led by veterinary scientists, created the novel vaccine using a proven "scaffold". Essentially, the core design of this vaccine is the same to one commonly employed to vaccinate elephants against a virus called a related virus.

The researchers incorporated this immunization framework with proteins from EEHV - non-infectious parts of the virus that the elephant's immune system might recognise and react against.

In a world-first trial, the team tested the new vaccine in several fit, mature elephants at Chester Zoo, then examined blood samples from the vaccinated animals.

The lead researcher stated that the results, published in a scientific journal, were "more successful than anticipated".

"The results demonstrated, unequivocally that the vaccine was effective to activate the generation of immune cells, that are crucial to combating viral infections."

Future Steps

The next step for the scientists is to try the vaccine in more juvenile elephants, which are the animals most at risk to severe disease.

The present immunization requires multiple shots to be given, so an additional objective is to determine if the same effective dose can be provided in a more straightforward way - perhaps with less injections.

The conservation scientist clarified: "In the end we want to employ 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 believe this is a significant step forward, and not just solely for the elephants, but because it additionally demonstrates that you can design and use vaccines to assist threatened animals."