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Scientists have made a major advance in creating a new immunization to combat a fatal virus that targets juvenile elephants.

The vaccine, produced by an international scientific group, is designed to stop the serious disease caused by EEHV, which is currently a leading cause of death in juvenile Asian elephants.

In tests that involved adult elephants at the facility, the vaccine was found to be safe and, importantly, to stimulate part of the immune system that assists in fighting viruses.

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

It is anticipated that the outcome of this first-of-its-kind trial will pave the way to averting the fatalities of young elephants from the dangerous condition caused by this virus.

Severe Consequences

EEHV has had a particularly devastating effect in zoos. At one facility alone, multiple young elephants have succumbed to it over the last decade. It has also been detected in wild elephant herds and in certain sanctuaries and care centers.

It causes a haemorrhagic disease - unchecked bleeding that can be fatal within a day. It leads to death in more than 80% of cases in juvenile elephants.

Understanding the Threat

Why EEHV can be so lethal is remains unclear. Numerous adult elephants carry the virus - apparently with no adverse effects on their health. But it is believed that juvenile calves are particularly susceptible when they are being weaned, and when the protective antibodies from the maternal nutrition decrease.

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

"It impacts 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."

Immunization Creation

The research team, led by animal health experts, created the new vaccine using a proven "framework". Essentially, the basic structure of this vaccine is the same to one routinely used to immunise elephants against a virus called a related virus.

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

In a pioneering experiment, the team evaluated the new vaccine in three healthy, mature elephants at Chester Zoo, then analysed blood tests from the innoculated animals.

Prof Steinbach stated that the findings, published in a research publication, were "more successful than anticipated".

"They showed, clearly that the vaccine was effective to activate the generation of T 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 animals most at risk to serious illness.

The current vaccination requires four injections to be given, so another aim is to work out if the same effective amount can be given in a simpler way - possibly with less jabs.

Dr Edwards clarified: "Ultimately we aim to employ this vaccine in the elephants that are in danger, so we want to make sure that we can deliver it to where it's needed."

Prof Steinbach continued: "We think this is a significant advancement, and not necessarily only for the elephants, but because it also demonstrates that you can develop and apply vaccines to help endangered species."