Henipavirus is a genus of negative-strand RNA viruses in the family Paramyxoviridae, order Mononegavirales containing six established species,[1][2] and numerous others still under study.

[7][8] In 2009, RNA sequences of three novel viruses in phylogenetic relationship to known henipaviruses were detected in African straw-colored fruit bats (Eidolon helvum) in Ghana.

[18][19] Deviation from the rule of six, through mutation or incomplete genome synthesis, leads to inefficient viral replication, probably due to structural constraints imposed by the binding between the RNA and the N protein.

This specific process in henipaviruses involves the insertion of extra guanosine residues into the P gene mRNA prior to translation.

P, V, and W possess an alternate open reading frame which results in production of C. P, V, W, and C are known to disrupt the host innate antiviral immune response through several different mechanisms.

The World Health Organization has classified henipaviral agents as R&D Blueprint Priority Pathogens, indicating that they pose a significant risk due to their epidemic potential.

A soluble HeV attachment glycoprotein vaccine designed to protect against NiV completed a phase I clinical trial in November 2022, but results have not yet been published.

[32] However, a number of preclinical vaccine studies in animal models of disease have identified that the cell-mediated immune response including CD8+ and CD4+ T-cells may play a role in protection.

The emergence of each of these viruses has been linked to an increase in contact between bats and humans, sometimes involving an intermediate domestic animal host.