Researchers have made a major advance in creating a new vaccine to prevent a fatal virus that affects young elephants.
The inoculation, produced by an global research team, is designed to prevent the serious illness caused by EEHV, which is presently a leading cause of death in juvenile Asian elephants.
In tests that included adult elephants at Chester Zoo, the vaccine was found to be harmless and, crucially, to activate part of the body's defenses that helps combating viruses.
Prof Falko Steinbach 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 trial will open the door to averting the fatalities of young elephants from the harmful condition caused by this virus.
Devastating Impact
EEHV has had a especially devastating impact in captive environments. At Chester Zoo alone, multiple baby elephants have succumbed to it over the last decade. It has additionally been detected in wild elephant herds and in certain sanctuaries and elephant orphanages.
It causes a haemorrhagic disease - unchecked bleeding that can be deadly within 24 hours. It results in death in more than 80% of cases in young elephants.
Comprehending the Danger
Why EEHV can be so dangerous is remains unclear. Numerous adult elephants host 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 maternal nutrition decrease.
At this stage, a calf's immune system is in a precarious state and it can become overwhelmed. "It can cause really severe illness," Dr Katie Edwards explained.
"It impacts elephants in nature, but we lack an precise count of how many fatalities in total it has caused. For elephants in human care though, there have been over a hundred deaths."
Immunization Creation
The research team, headed by animal health experts, created the novel vaccine using a proven "scaffold". Essentially, the core design of this vaccine is the same to one commonly employed to immunise elephants against a virus called a related virus.
The researchers incorporated this vaccine structure with components from EEHV - harmless bits of the virus that the animal's immune system might recognise and respond to.
In a pioneering trial, the team evaluated the novel vaccine in three healthy, adult elephants at Chester Zoo, then examined blood samples from the vaccinated animals.
Prof Steinbach commented that the findings, released in a scientific journal, were "more successful than anticipated".
"They showed, clearly that the vaccine was effective to stimulate the generation of T cells, that are vital to combating virus attacks."
Future Steps
The next step for the researchers is to test the vaccine in younger elephants, which are the animals most at risk to severe illness.
The current vaccination involves four shots to be administered, so another aim is to determine if the equivalent protective dose can be given in a simpler way - perhaps with fewer injections.
The conservation scientist explained: "Ultimately 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 necessary."
Prof Steinbach 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 endangered species."
