The experimental mRNA injection rollout has now reached endangered baby elephants. On October 8, 2026, the Saint Louis Zoo announced that a 1½-year-old Asian elephant named Jet had received his third dose of an experimental mRNA injection targeting elephant endotheliotropic herpesvirus (EEHV).
Developed by Baylor College of Medicine in collaboration with zoo researchers, the gene therapy uses lipid nanoparticles to deliver four synthetic mRNA sequences encoding EEHV viral proteins.
Experimental mRNA Gene Therapy Is Expanding Across American Zoos
The research program involves institutions including Houston Zoo, Cincinnati Zoo, Fort Worth Zoo, Rosamond Gifford Zoo, and White Oak Conservation. Saint Louis Zoo has now publicly confirmed vaccinating its young elephant.
A peer-reviewed study published in the Journal of Virology in July 2026 evaluated the gene therapy in nine Asian elephants. Elephants received up to FOUR injections containing 400 micrograms of mRNA each. Three of six initially antibody-negative elephants failed to develop detectable antibody responses after their first two injections and required additional booster shots.
Vaccinated Elephants Still Contracted EEHV
Perhaps most notably, a second peer-reviewed study published in the Journal of Virology documented that two juvenile elephants at Cincinnati Zoo developed confirmed EEHV infections after receiving two doses of the experimental mRNA injection.
Both animals received their injections in October and November 2024 before testing positive in February and March 2025. The findings show that the mRNA gene therapy does not reliably prevent EEHV infection in elephants.
The expansion of dangerous mRNA technology into endangered wildlife already facing the threat of extinction marks a disturbing new frontier in veterinary medicine.
Epidemiologist and Foundation Administrator, McCullough Foundation
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The Lord God of Heaven and earth sees. He’ll have the last say.
I hear vets are using them in our pets. I refuse to take my animals to a vet now.