Brazos, a two-year-old Asian elephant at the Fort Worth Zoo, may help cure a fatal viral infection killing young elephants in the wild and in captivity.
Brazos was recently vaccinated with a revolutionary vaccine that targets elephant endotheliotropic herpesvirus (EEHV), the zoo announced Thursday. This virus naturally infects elephants but usually remains dormant. Scientists don’t know why or how the virus becomes activated, but once it does, it can cause a rapid and fatal hemorrhagic disease that is the leading cause of death in Asian elephant calves and young African elephants.
“Vaccinating Brazos is a huge step toward preventing EEHV deaths in elephants,” Sarah Cannizzo, an associate veterinarian at the Fort Worth Zoo, said in a prepared statement. “It is an awesome example of the power of collaboration: collaboration across zoos, collaboration among zoos and scientists, and collaboration between elephant and veterinary departments.”
In 1995, Kumari, a 16-month-old Asian elephant at the National Zoo in Washington, D.C., was the first to be diagnosed with the virus. This set in motion decades of research to understand the virus and to develop tests that can detect it.
A first-of-its-kind vaccine was developed by Paul Ling, a virologist at the Baylor College of Medicine, and given in June to a 40-year-old Asian elephant at the Houston Zoo. The vaccine targets a strain of the virus that tends to be found in Asian elephants. Much like a COVID vaccine, it uses mRNA to teach an elephant’s immune cells to recognize and fight the disease.
While three other Asian elephants at the Houston Zoo have since received the vaccine, Brazos is unique in that he didn’t have any antibodies against the virus. At birth, an elephant mother passes on her antibodies to her calf, but these antibodies disappear over time. This is why young elephants are so susceptible to the disease. The Fort Worth Zoo regularly monitors the antibody status of its elephants; no antibodies were found in Brazos’ recent blood test.
His vaccination, which involved an initial shot and a booster, will allow researchers to see how well it works in an elephant that has not been infected with the virus or retained antibodies from its mother.
“Should these vaccine efforts be successful and lead to wide-spread adoption of the vaccine, Brazos will be one of a small handful of elephants who helped make this possible,” Ling said in a statement.
Miriam Fauzia is a science reporting fellow at The Dallas Morning News. Her fellowship is supported by the University of Texas at Dallas. The News makes all editorial decisions.
