Scientists have made a major advance in creating a novel immunization to combat a deadly virus that targets juvenile elephants.
The vaccine, developed by an international scientific group, aims to prevent the severe disease caused by elephant endotheliotropic herpesvirus (EEHV), which is presently a leading cause of death in juvenile Asian elephants.
In trials that included mature elephants at Chester Zoo, the vaccine was found to be harmless and, crucially, to activate part of the immune system that helps fighting viruses.
Prof Falko Steinbach called this as "a pivotal step in our work to protect Asian elephants".
It is hoped that the result of this first-of-its-kind trial will pave the way to preventing the fatalities of young elephants from the dangerous disease caused by this virus.
Severe Consequences
EEHV has had a particularly destructive effect in captive environments. At one facility by itself, multiple baby elephants have died to it over the past ten years. It has additionally been found in wild elephant herds and in certain sanctuaries and care centers.
It causes a bleeding disorder - uncontrolled bleeding that can be deadly within a day. It results in death in over eighty percent of cases in juvenile elephants.
Understanding the Threat
Why EEHV can be so lethal is still unclear. Numerous adult elephants carry the virus - seemingly with no adverse effects on their health. But it is believed that young calves are particularly susceptible when they are being transitioned from milk, and when the immune-boosting defenses from the maternal nutrition decrease.
At this phase, a young elephant's natural defenses is in a delicate balance and it can become overpowered. "It may lead to really severe disease," a lead conservation scientist explained.
"It does affect wild elephants, but we don't have an precise count of how many deaths in overall it has caused. For elephants in human care however, there have been more than 100 deaths."
Vaccine Development
The research team, led by animal health experts, developed the new 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 cowpox.
The scientists seeded this immunization framework with components from EEHV - harmless bits of the virus that the elephant's immune system might identify and react against.
In a pioneering trial, the team tested the novel vaccine in several healthy, adult elephants at the zoo, then examined blood tests from the vaccinated animals.
Prof Steinbach stated that the results, published in a scientific journal, were "better than we had hoped for".
"The results demonstrated, unequivocally that the vaccine was effective to stimulate the generation of T cells, that are vital to combating viral infections."
Next Phases
The next step for the researchers is to try the vaccine in more juvenile elephants, which are the creatures most at risk to severe illness.
The current immunization requires multiple injections to be administered, so another aim is to work out if the same protective dose can be provided in a more straightforward way - perhaps with fewer injections.
The conservation scientist clarified: "In the end we want to employ this vaccine in the elephants that are at risk, so we want to ensure that we can get it to where it's needed."
The project lead added: "We believe this is a significant step forward, and not just only for the elephants, but because it also demonstrates that you can design and apply vaccines to assist threatened animals."
