In both cases, the virus is often lethal to humans but not nearly so consequential as it would be if not constrained by the limits of its transmissibility. It has no preternatural powers. It finds humans a dead-end host. People are ignorant about its actual properties and inclined to imagine an unreal breadth of risk. Among differences between the two, there’s this: Ebola is infamous and herpes B is largely unknown. It’s unknown, that is, unless you work in a monkey lab or run a safari park.
