Arenaviruses

Arenaviruses are a diverse family of enveloped RNA viruses primarily associated with rodent reservoirs, but capable of zoonotic transmission to humans. These viruses are responsible for a range of diseases, from mild neurological illness to severe and often fatal viral hemorrhagic fevers (VHFs), such as Lassa fever in West Africa and Argentine hemorrhagic fever in South America. Lassa virus (LASV) and Junín virus (JUNV)—the most studied Old World and New World arenaviruses, respectively—are classified as biosafety level 4 (BSL-4) agents and designated priority pathogens.

Despite causing significant disease burden and being listed as Federal Select Agents in the U.S., arenaviruses remain understudied. Critical gaps exist in understanding their ecology, mechanisms of pathogenesis, and immune evasion strategies. There are no licensed vaccines or therapeutics for most arenaviruses, except for the JUNV vaccine in Argentina. Experimental platforms—such as monoclonal antibodies, ribavirin, and VSV-based vaccines—have shown promise, particularly against LASV in nonhuman primate models. However, the high genetic and antigenic diversity within the Arenaviridae family complicates the development of broadly effective medical countermeasures.

Explore our latest articles to stay informed on the evolving science, policies, and innovations shaping the response to arenavirus threats.