Antiviral activity of PHA767491 on Caprine alphaherpesvirus 1 in vitro

Caprine alphaherpesvirus 1 (CpHV-1) induces genital lesions in its natural host similar to those caused by Human alphaherpesvirus 2 (HHV-2), commonly named herpes simplex virus 2 (HSV-2) in human patients. CpHV-1 infection in goats could represent a useful homologous animal model for the study of HSV-2 infection, chiefly for the assessment of antiviral drugs in in vivo studies. PHA767491 is a potent inhibitor of HSV-1 and HSV-2, being able to limit replication of HHVs both in vitro and in the mouse model. In the present study the antiviral efficacy of PHA767491 against CpHV-1 was evaluated in vitro in MDBK cells. PHA767491 inhibited significantly CpHV-1 replication in a dose-dependent fashion by up to 2.50 log10 TCID50/50 μl and was able to decrease viral DNA by nearly 8 log10. These findings confirm that PHA767491 is highly effective not only against simplexviruses (HSV-1 and HSV-2), but also against the varicellovirus CpHV-1. Experiments will be necessary to assess whether PHA767491 is suitable for treatment of vaginal lesions in CpHV-1-goat model. This could provide hints for the therapy of genital alphaherpesvirus infections in humans.