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

The vaccine, developed by an international research team, aims to stop the severe disease caused by EEHV, which is currently a primary cause of death in young Asian elephants.

In tests that included adult elephants at the facility, the vaccine was found to be safe and, crucially, to activate part of the immune system that helps combating viruses.

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

It is hoped that the result of this first-of-its-kind study will pave the way to averting the deaths of juvenile elephants from the harmful disease caused by this virus.

Severe Consequences

EEHV has had a especially devastating impact in zoos. At one facility alone, seven young elephants have succumbed to it over the last decade. It has additionally been detected in wild elephant herds and in certain refuges and elephant orphanages.

It causes a haemorrhagic disease - uncontrolled hemorrhaging that can be fatal within a day. It results in death in over eighty percent of instances in juvenile elephants.

Comprehending the Danger

Why EEHV can be so dangerous is remains unknown. Many adult elephants host the virus - apparently with no adverse effects on their well-being. But it is thought that young calves are particularly susceptible when they are being transitioned from milk, and when the immune-boosting antibodies from the mother's milk decline.

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

"It does affect elephants in nature, but we lack an precise count of how many deaths in total it has caused. For elephants in human care however, there have been over a hundred deaths."

Vaccine Development

The scientific group, headed by animal health experts, created the new vaccine using a tried and tested "framework". Essentially, the basic structure of this vaccine is identical to one routinely used to vaccinate elephants against a virus called a related virus.

The researchers incorporated this immunization framework with proteins from EEHV - harmless bits of the virus that the animal's defense system might recognise and react against.

In a pioneering experiment, the team evaluated the novel vaccine in several fit, adult elephants at the zoo, then examined blood samples from the vaccinated animals.

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

"They showed, clearly that the vaccine was able to stimulate the generation of T cells, that are crucial to fighting viral infections."

Next Phases

The subsequent phase for the researchers is to test the vaccine in younger elephants, which are the animals most at risk to severe disease.

The current vaccination requires multiple shots to be administered, so an additional objective is to determine if the same protective dose can be provided in a more straightforward way - perhaps with less jabs.

Dr Edwards explained: "In the end we want to employ this vaccine in the elephants that are at risk, so we want to ensure that we can deliver it to where it's necessary."

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