This report describes development towards potential new vaccines for EHV-1. Firstly the immunogenicity of a formulation containing EHV-1 envelope glycoproteins was tested by measuring antibody responses of mares and young foals. Secondly, in order to provide a system whereby these and other vaccines could be assessed, an experimental EHV-1 respiratory challenge model of infection was established in mares and foals, using an Australian isolate of EHV-1. This model was then used to determine whether the immune responses to the glycoprotein formulation could provide protection against EHV-1 infection.