Researchers have made a major advance in developing a novel immunization to prevent a deadly virus that targets juvenile elephants.
The vaccine, produced by an international scientific group, is designed to stop the severe illness caused by EEHV, which is presently a primary cause of death in young Asian elephants.
In tests that involved mature elephants at Chester Zoo, the vaccine was found to be safe and, crucially, to stimulate part of the body's defenses that assists in fighting viruses.
A lead scientist described this as "a landmark moment in our efforts to protect Asian elephants".
It is hoped that the outcome of this first-of-its-kind study will pave the way to averting the fatalities 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 by itself, seven baby elephants have succumbed to it over the past ten years. It has also been found in natural populations and in certain sanctuaries and elephant orphanages.
It causes a bleeding disorder - uncontrolled hemorrhaging that can be deadly within a day. It leads to death in over eighty percent of instances in juvenile elephants.
Understanding the Threat
Why EEHV can be so lethal is remains unknown. Numerous adult elephants carry the virus - seemingly with no negative impact on their health. But it is believed that juvenile calves are especially vulnerable when they are being weaned, and when the protective antibodies from the mother's milk decrease.
At this phase, a calf's natural defenses is in a precarious balance and it can become overpowered. "It may lead to extremely serious illness," a lead conservation scientist explained.
"It impacts wild elephants, but we don't have an precise count of how many deaths in overall it has resulted in. For elephants in human care however, there have been over a hundred deaths."
Vaccine Development
The research team, led by animal health experts, developed the novel vaccine using a proven "framework". Basically, the core design of this vaccine is the same to one routinely used to vaccinate elephants against a virus called cowpox.
The researchers seeded this vaccine structure with components from EEHV - non-infectious bits of the virus that the animal's defense system might recognise and react against.
In a world-first experiment, the team evaluated the new vaccine in several healthy, mature elephants at the zoo, then analysed blood tests from the vaccinated animals.
The lead researcher stated that the results, released in a scientific journal, were "more successful than anticipated".
"They showed, unequivocally that the vaccine was effective to stimulate the production of T cells, that are crucial to fighting viral infections."
Next Phases
The next step for the scientists is to try the vaccine in more juvenile elephants, which are the animals most at risk to serious illness.
The current immunization requires multiple shots to be given, so another aim is to work out if the equivalent effective dose can be given in a simpler way - possibly with less jabs.
Dr Edwards explained: "In the end we want to employ this vaccine in the elephants that are at risk, so we need to ensure that we can get it to where it's needed."
Prof Steinbach added: "We think this is a major step forward, and not just only for the elephants, but because it additionally shows that you can design and use vaccines to assist endangered species."
