BoDV-1/2 have the smallest genome (8.9 kilobases) of any Mononegavirales member and are unique within that order in their ability to replicate within the host cell nucleus.

P24 is encoded by open reading frame II (ORF-II) and undergoes high rates of mutation in humans.

[5] Horse and human P24 have no species-specific amino acid residues, suggesting that the two viruses are related.

[8] BoDV-1 p24 RNA has been detected in the peripheral blood mononuclear cells (PBMCs) of psychiatric patients with such conditions.

Endogenous viral elements homologous to the nucleoprotein gene of BoDV-1 have been shown to exist in the genomes of several mammalian species, including humans and non-human primates.

[12] A Bayesian analysis of Borna disease virus 1 suggests that the current strains diversified ~300 years ago and that avian-host bornaviruses evolved considerably earlier than this.