Medgene Launches First US Vaccine Against Cattle-Killing Theileria

Theileria poses a significant threat to the U.S. cattle industry, where tick-borne pathogens account for over $13.9 billion in annual losses. Transmitted via the saliva of feeding ticks—specifically the invasive Asian longhorned tick—the parasite causes fever, jaundice, and reproductive failure. Because survivors remain lifelong carriers, the pathogen creates a persistent drain on milk production and herd health. Unlike other bovine infections, this parasite frequently targets young calves and pregnant heifers, compounding its economic impact.

Medgene’s new vaccine uses a two-shot series to target both the sporozoite and merozoite stages of the parasite's lifecycle, providing veterinarians with a preventive tool against an infection that can circulate through a herd before initial symptoms are even diagnosed. The company, which utilizes its proprietary Spice bioinformatics system to develop animal-origin-free biologics, notes that the vaccine is available immediately by prescription. While the vaccine addresses a critical gap in veterinary medicine, the company specifies that the potency and efficacy of these prescription platform biologics are determined by the prescribing veterinarian.