Houston is making history for elephants around the world. After more than 15 years of teamwork, Houston Zoo and Baylor College of Medicine have announced a landmark breakthrough in the fight against EEHV, a herpesvirus that is the leading cause of death in young Asian elephants.
Two companion studies published in the Journal of Virology describe the world’s first mRNA vaccine developed for elephants and the first peer-reviewed evidence that vaccinated young elephants can fight off a natural infection without falling seriously ill. In the study, nine Asian elephants at five zoos, including Houston Zoo, showed strong, lasting immune responses to the vaccine.
Then came the most hopeful moment of all: two vaccinated juvenile elephants at Cincinnati Zoo later encountered the virus in the wild of everyday life, stayed healthy, needed no treatment, and recovered on their own without developing the dangerous hemorrhagic disease. It is the first clinical evidence that a vaccine can protect elephants from EEHV.
The partnership began back in 2009 after Houston Zoo lost a young elephant to the virus, and it reached a historic milestone on June 18, 2024, when Tess, an Asian elephant at Houston Zoo, became the very first elephant ever vaccinated. Her fellow elephants Winnie and Teddy joined the study too.
“These findings offer real hope and bring us one step closer to changing the future for elephants,” said Lisa Peterson, President and CEO of Houston Zoo. Researchers are already working on next-generation vaccines, including approaches for African elephants, so that more calves can survive and thrive. Houston’s science is giving the world’s elephants a brighter tomorrow.
Photo: Houston Zoo
