Category: Wildlife Conservation

Development of Vaccine for EEHV in Young Elephants

A novel vaccine has been produced to protect young elephants from Elephant Endotheliotropic Herpesvirus (EEHV), a potentially fatal virus that can result in death within 24 hours. Initially, young calves are shielded by maternal immunity, but as they mature, they become vulnerable to the virus, particularly prevalent in Asian elephants.

While adult Asian elephants are not significantly threatened by EEHV, young elephants with undeveloped immune systems are at serious risk. Researchers from Chester Zoo, the University of Surrey, and the Animal and Plant Health Agency have developed a vaccine to protect these young elephants.

According to the International Union for Conservation of Nature (IUCN), the Asian elephant is classified as endangered, with fewer than 40,000 individuals remaining. The virus has caused fatalities in regions such as India, Nepal, Myanmar, and Thailand, and has impacted elephant conservation and breeding programs globally, prompting the focus on the Asian species for vaccine development.

Proof of Concept and Vaccine Development

The proof of concept for the vaccine involved a trial at Chester Zoo, where elderly male elephant Aung Bo was one of three elephants participating. The study, co-authored by Dr. Falko Steinbach, Professor of Veterinary Immunology at the University of Surrey, has been published in Nature Communications. The vaccine is designed not to prevent infection but to enhance the immune system’s ability to combat the virus and prevent severe disease or death.

Vaccine Mechanism

Traditional vaccines often utilize weakened virus strains, but this approach was not feasible for EEHV due to the inability to culture the virus externally. Instead, researchers focused on the genetic sequencing of the virus to identify suitable candidates for stimulating the immune response. The vaccine employs a heterologous approach, utilizing two delivery methods with key viral components, and is administered via injection with booster doses, making it suitable for use in controlled environments like zoos and sanctuaries.

Dr. Katie Edwards, Lead Conservation Scientist at Chester Zoo, notes that once symptoms appear in young elephants, intervention is often too late. The new vaccine strategically targets specific immune system components, using technology not previously applied to wildlife. This approach could potentially be adapted for other species and viruses.

The research team aims to further develop the vaccine for potential application in wild elephant populations.