Vaccine Advancement for Deadly Elephant Viral Disease

Scientists have made a major advance in developing a novel immunization to combat a deadly virus that affects young elephants.

The vaccine, produced by an global research team, is designed to prevent the severe illness caused by elephant endotheliotropic herpesvirus (EEHV), which is currently a leading cause of death in juvenile Asian elephants.

In tests that included mature elephants at Chester Zoo, the vaccine was found to be harmless and, importantly, to activate part of the immune system that assists in combating viruses.

Prof Falko Steinbach called this as "a pivotal step in our efforts to safeguard Asian elephants".

It is anticipated that the outcome of this pioneering trial will open the door to averting the fatalities of young elephants from the dangerous disease caused by this virus.

Severe Consequences

EEHV has had a particularly devastating impact in captive environments. At Chester Zoo alone, multiple baby elephants have died to it over the past ten years. It has additionally been found in natural populations and in some sanctuaries and care centers.

It causes a bleeding disorder - unchecked bleeding that can be fatal within 24 hours. It leads to death in over eighty percent of cases in young elephants.

Understanding the Threat

Why EEHV can be so dangerous is still unknown. Numerous adult elephants carry the virus - apparently with no adverse effects on their health. But it is thought that young elephants are especially vulnerable when they are being weaned, and when the protective antibodies from the mother's milk decline.

At this phase, a young elephant's natural defenses is in a precarious balance and it can become overpowered. "It can cause extremely serious disease," Dr Katie Edwards stated.

"It impacts elephants in nature, but we lack an precise count of how many fatalities in total it has resulted in. For elephants in human care though, there have been more than 100 deaths."

Immunization Creation

The research team, led by animal health experts, created the new vaccine using a proven "framework". Essentially, the core design of this vaccine is identical to one routinely used to immunise elephants against a virus called cowpox.

The scientists seeded this vaccine structure with proteins from EEHV - harmless parts of the virus that the animal's defense system might identify and respond to.

In a pioneering experiment, the team evaluated the novel vaccine in three healthy, mature elephants at Chester Zoo, then analysed blood samples from the vaccinated animals.

Prof Steinbach commented that the results, published in a research publication, were "better than we had hoped for".

"The results demonstrated, unequivocally that the vaccine was able to activate the production of T cells, that are vital to combating viral infections."

Future Steps

The next step for the scientists is to try the vaccine in younger elephants, which are the creatures most at risk to serious illness.

The present immunization requires four shots to be given, so another aim is to determine if the equivalent protective amount can be provided in a simpler way - perhaps with less injections.

Dr Edwards clarified: "Ultimately we aim to use this vaccine in the elephants that are in danger, so we want to ensure that we can deliver it to where it's necessary."

Prof Steinbach continued: "We think this is a significant step forward, and not necessarily only for the elephants, but because it also demonstrates that you can design and apply vaccines to help endangered species."