Scientists have made a major advance in developing a new vaccine to prevent a fatal virus that targets young elephants.
The inoculation, produced by an international research team, is designed to stop the severe illness caused by EEHV, which is currently a primary cause of death in juvenile Asian elephants.
In trials that involved mature elephants at the facility, the vaccine was found to be harmless and, crucially, to activate part of the body's defenses that helps 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 pioneering study will pave the way to preventing the fatalities of juvenile elephants from the dangerous condition caused by this virus.
Severe Consequences
EEHV has had a especially devastating effect in captive environments. At Chester Zoo alone, seven baby elephants have succumbed to it over the last decade. It has additionally been found in natural populations and in some sanctuaries and elephant orphanages.
It causes a haemorrhagic disease - uncontrolled bleeding that can be deadly within 24 hours. It results in death in more than 80% of instances in juvenile elephants.
Understanding the Threat
Why EEHV can be so dangerous is remains unclear. Many adult elephants carry the virus - apparently with no negative impact on their well-being. But it is thought that young calves are especially vulnerable when they are being transitioned from milk, and when the protective defenses from the mother's milk decline.
At this stage, a calf's natural defenses is in a precarious state and it can become overpowered. "It may lead to really severe disease," Dr Katie Edwards explained.
"It does affect elephants in nature, but we don't have an precise count of how many fatalities in total it has resulted in. For elephants in captivity however, there have been over a hundred deaths."
Immunization Creation
The scientific group, headed by veterinary scientists, created the novel vaccine using a tried and tested "scaffold". Basically, the core design of this vaccine is the same to one routinely used to vaccinate elephants against a virus called a related virus.
The scientists seeded this vaccine structure with proteins from EEHV - non-infectious parts of the virus that the animal's defense system might recognise and react against.
In a world-first trial, the team tested the new vaccine in several fit, adult elephants at the zoo, then analysed blood samples from the vaccinated animals.
The lead researcher stated that the findings, published in a scientific journal, were "better than we had hoped for".
"They showed, unequivocally that the vaccine was able to stimulate the generation of immune cells, that are crucial to fighting viral infections."
Next Phases
The next step for the researchers is to try the vaccine in more juvenile elephants, which are the animals most at risk to serious disease.
The present vaccination requires multiple injections to be given, so an additional objective is to determine if the same effective dose can be given in a simpler way - perhaps with less jabs.
Dr Edwards clarified: "Ultimately we want to employ this vaccine in the elephants that are at risk, so we need to make sure that we can get it to where it's necessary."
The project lead continued: "We think this is a major step forward, and not just solely for the elephants, but because it additionally shows that you can design and apply vaccines to help threatened animals."
