Equine immunity to viruses

This article reviews immune responses to equine respiratory virus infection s and considers typical immune responses to acute (equine influenza and ade novirus) infections and chronic/persistent (equid herpesvirus-l and equine arteritis virus) infections. Innate and adaptive equine immune reponses to respiratory viruses are described, extrapolating from human and murine immu nology where necessary. The salient features of immunity to the acute virus infections are contrasted with the immune responses to chronic virus infec tions. Although antibody is important in recovery from acute virus infectio ns, cytotoxic T-lymphocyte responses are critical in recovery from chronic virus infections. Future effective vaccines against chronic virus infection s must therefore stimulate T-lymphocyte responses in addition to mucosal an d circulating antibody.