Fighting the Calf Killer

There are few occasions in a zoo that are cause for more celebration than the birth of an elephant.  Though they have been kept under human care for thousands of years, it is only relatively recently - the past few decades - the births starting occurring outside of Africa and Asia, and each newborn represents painstaking work and almost two years of fretting through the gestation period.  The anxiety doesn't end at birth, however.  Among Asian elephants, about half of all calves are stricken down by a silent killer.

By the time that the symptoms - lethargy, lesions - appear, it's usually too late.  The elephant could be dead in as little as 24 hours.  Those are the signs that the animal is suffering from Elephant Endotheliotrophic Herpesvirus - EEHV.  It usually strikes calves between one-and-a-half and three years of age, and is fatal in about 80% of cases.  Antiviral drugs are available, but not terribly effective, working in only about one-third of the cases.  The disease does not seem to pose much of a problem for African elephants; it's possible that the virus was endemic to them and they have resistance to it, which their Asian counterparts lack.  Of special concern is that the virus is starting to appear more frequently in wild Asian elephants, posing an additional threat to an already endangered species.  Just this year, EEHV already claimed the lives of two young Asian elephants at the Albuquerque BioPark Zoo in New Mexico.

Indali is now thriving, having survived her brush with the virus in 2019 - Chester Zoo

There is cause for hope, however.  The University of Surrey and the Chester Zoo (home to one of the rare survivors of the disease, a now 5-year-old female named Indali) are beginning the trials of a vaccine.  Not only could this potentially be a life-saver for zoo elephants (and for boosting the population - it could effectively double the number of calves that survive to adulthood), there is also the possibility of vaccinating wild herds to protect them from the virus.  In zoos, at least, the vaccination process (and the blood collection that goes into it) will only be possibly through the close relationship that elephants form with their trainers.  With luck, it could make tragic deaths such as those which devastated Albuquerque a thing of the past, as anachronistic as smallpox in our own species.

Vaccine trail for killer elephant virus begins