The aim of this study was to evaluate three commercially available ILTV vaccine strains and a glycoprotein G (gG) deletion mutant ILTV vaccine candidate (ΔgG ILTV) [11] for their ability to establish latent infections in TG of specific pathogen free (SPF) birds following eye-drop inoculation. The gene discussed is THBS1; the disease is disease arising from reactivation of latent virus.