Hendra virus: research progress on a bat-borne threat lurking at the human-animal interface

Hendra virus (HeV) is a highly lethal zoonotic henipavirus that has caused recurrent cross-species spillover events in Australia since 1994. Its capacity for cross-species spillover, together with its tropism for vascular endothelial and neural tissues, makes HeV important to veterinary medicine and public health. Flying foxes are the natural reservoir hosts, and horses act as intermediate and amplifying hosts through which all confirmed human infections have occurred. Detection of antibodies and viral RNA from related henipaviruses in Southeast Asian bats indicates regional henipavirus diversity and a possible broader henipavirus spillover risk, but does not demonstrate HeV circulation or transmission in Southeast Asia. Human HeV infection is rare but can cause severe respiratory and neurological disease. From a veterinary-oriented One Health perspective, this review integrates current evidence on viral biology, transmission, clinical disease, diagnostics, animal models, equine vaccination, and clinical-stage vaccines and antibody-based interventions, with particular attention to HeV-g2-associated diagnostic challenges and the role of equine vaccination in reducing occupational exposure.