Scientists have achieved a major advance in creating a novel vaccine to combat a deadly virus that targets juvenile elephants.
The vaccine, produced by an international scientific group, is designed to prevent the severe illness caused by EEHV, which is currently a primary cause of death in juvenile Asian elephants.
In tests that included adult elephants at the facility, the vaccine was found to be safe and, importantly, to stimulate components of the body's defenses that assists in fighting viruses.
Prof Falko Steinbach called this as "a pivotal step in our efforts to safeguard Asian elephants".
It is hoped that the result of this first-of-its-kind trial will pave the way to preventing the deaths of juvenile elephants from the dangerous condition caused by this virus.
Devastating Impact
EEHV has had a particularly destructive impact in captive environments. At one facility alone, multiple baby elephants have died to it over the past ten years. It has additionally been detected in wild elephant herds and in certain refuges and elephant orphanages.
It causes a haemorrhagic disease - unchecked hemorrhaging 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 dangerous is remains unknown. Numerous adult elephants host the virus - apparently with no adverse effects on their health. But it is thought that juvenile calves are particularly susceptible when they are being transitioned from milk, and when the immune-boosting antibodies from the maternal nutrition decrease.
At this stage, a young elephant's natural defenses is in a delicate balance and it can become overpowered. "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 deaths in overall it has caused. For elephants in human care however, there have been over a hundred deaths."
Immunization Creation
The research team, led by veterinary scientists, developed the novel vaccine using a proven "scaffold". Essentially, the core design of this vaccine is identical to one commonly employed to immunise elephants against a virus called a related virus.
The scientists seeded this immunization framework with components from EEHV - non-infectious parts of the virus that the elephant's immune system might identify and respond to.
In a world-first trial, the team tested the new vaccine in three fit, mature elephants at Chester Zoo, then examined blood tests from the innoculated animals.
Prof Steinbach stated that the results, published in a research publication, were "more successful than anticipated".
"The results demonstrated, clearly that the vaccine was effective to activate the generation of T cells, that are vital to fighting viral infections."
Next Phases
The subsequent phase for the scientists is to test the vaccine in more juvenile elephants, which are the animals most vulnerable to serious disease.
The current immunization requires four injections to be given, so an additional objective is to work out if the same effective amount can be given in a more straightforward way - possibly with less jabs.
The conservation scientist clarified: "Ultimately we aim to use this vaccine in the elephants that are in danger, so we need to ensure that we can deliver it to where it's necessary."
The project lead added: "We believe this is a major step forward, and not necessarily only for the elephants, but because it additionally demonstrates that you can design and apply vaccines to assist threatened animals."
