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Scientists have achieved a breakthrough in developing a novel immunization to prevent a fatal virus that affects juvenile elephants.

The vaccine, developed by an international research team, aims to stop the severe illness caused by elephant endotheliotropic herpesvirus (EEHV), which is presently a primary cause of death in juvenile Asian elephants.

In tests that included adult elephants at Chester Zoo, the vaccine was found to be safe and, importantly, to activate part of the body's defenses that helps combating viruses.

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

It is hoped that the result of this pioneering trial will pave the way to preventing the deaths of young elephants from the dangerous disease caused by this virus.

Devastating Impact

EEHV has had a particularly devastating impact in zoos. At Chester Zoo alone, seven young elephants have died to it over the last decade. It has additionally been detected in natural populations and in some sanctuaries and care centers.

It causes a bleeding disorder - uncontrolled bleeding that can be fatal within 24 hours. It leads to death in more than 80% of cases in juvenile elephants.

Understanding the Threat

Why EEHV can be so dangerous is remains unknown. Numerous mature elephants host the virus - seemingly with no adverse effects on their health. But it is thought that young elephants are particularly vulnerable when they are being weaned, and when the protective antibodies from the maternal nutrition decline.

At this stage, a calf's natural defenses is in a precarious state and it can become overpowered. "It can cause really severe disease," a lead conservation scientist stated.

"It does affect elephants in nature, but we lack an precise count of how many deaths in total it has resulted in. For elephants in captivity though, there have been more than 100 deaths."

Immunization Creation

The scientific group, headed by veterinary scientists, developed the new vaccine using a tried and tested "framework". Basically, the basic structure of this vaccine is the same to one routinely used to immunise elephants against a virus called a related virus.

The scientists incorporated this vaccine structure with components from EEHV - harmless bits of the virus that the animal's immune system might identify and respond to.

In a pioneering trial, the team evaluated the new vaccine in several fit, mature elephants at the zoo, then examined blood samples from the vaccinated animals.

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

"The results demonstrated, unequivocally that the vaccine was able to stimulate the production of immune cells, that are crucial to combating viral infections."

Next Phases

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

The current vaccination requires multiple injections to be given, so an additional objective is to determine if the equivalent protective amount can be provided in a more straightforward way - perhaps with less jabs.

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

The project lead added: "We believe this is a significant advancement, and not necessarily solely for the elephants, but because it also demonstrates that you can develop and apply vaccines to assist endangered species."