Beyond the classic rabies virus: emerging lyssaviruses and future challenges for one health

Rabies is discussed as though one virus caused it. It does not. The genus Lyssavirus now contains eighteen ratified species and a lengthening queue of candidates, most of them maintained quietly in bats across five continents, and every one of them capable of producing the same fatal encephalitis. This review maps that hidden diversity and asks what it means for prevention. We summarise reservoir hosts, geographical range and documented human infections for the principal emerging lyssaviruses; explain how phylogroup structure in the viral glycoprotein decides whether a rabies vaccine will work; and appraise cross-neutralisation data, monoclonal antibody products and pan-lyssavirus vaccine candidates. We then test the diagnostic toolkit, from the direct fluorescent antibody test to portable nanopore sequencing, against the specific problem of detecting a virus nobody expected. Current biologicals reliably cover phylogroup I and little else. Closing that gap is a veterinary problem long before it becomes a medical one.