Current Therapies for Biosafety Level 4 Pathogens

Biosafety level 4 (BSL4) viruses including many filoviruses (e.g. Ebola and Marburg virus), henipaviruses (e.g. Nipah and Hendra virus), arenaviruses (e.g. Lassa and Junín virus), and bunyaviruses (Crimean Congo Hemorrhagic Fever virus) belong to the deadliest pathogens known to man, and cause severe hemorrhagic fever and/or neurological disease. Further, they have the ability to cause sizable outbreaks with the potential for human-to-human spread. Consequently, the development of countermeasures against these viruses has been recognized as an international priority, and there has been a drastic increase in early-stage research for therapies directed against many of them. While for some viruses these have advanced into human clinical testing, or even resulted in approved therapies, for the majority of BSL4 viruses this is not yet the case, and additional research is still required to address remaining challenges. This chapter provides information about the current state of therapy for each of these viruses and summarizes the antiviral strategies, based on both immunotherapies and small molecules, that have so far progressed the furthest in pre-clinical and/or clinical testing.