Host-specificity assessment of feline alphaherpesvirus-1 derived immunocontraceptive candidates in non-feline models

Feline alphaherpesvirus-1 (FHV-1) is generally considered to have a narrow host range restricted to the Felidae family. As a result, FHV-1 has been proposed as a potential vaccine vector to carry foreign pathogen or immunocontraceptive antigens, for use in domestic cat (Felis catus) populations. The species-specificity of FHV-1 has been described previously in the 1970s where several non-feline hosts were assessed for their inability to be infected by FHV-1. However, more recently, evidence of FHV-1 infection in BALB/c mice was reported, furthering the need for additional investigation into the host range potential of FHV-1. This study investigated the species-specificity of FHV-1 and three modified FHV-1 variants containing antigens intended as immunocontraceptive targets. Their ability to replicate in respiratory tissue, cause clinical signs and induce disruptions in female reproductive tissues was studied in an in vivo murine model. Furthermore, a diverse range of non-feline cell types originating from species including domestic animals, wildlife species and a non-human primate were also investigated for their ability to support FHV-1 immunocontraceptive replication in vitro. No evidence of FHV-1 replication was detected in vitro in the non-feline cell lines, nor was any evidence of disruption to female reproductive tissues or viral activity detected in the murine model. The findings contribute towards the global understanding of FHV-1 host range and add support for its use as a feline-specific viral vector.