Influenza virus infections and immunity: a review of human and animal models.

Studies of the pathogenesis of influenza infection have involved the extensive use of animal models. The development of the current concepts of immunity to influenza and of the contribution the secretory immune system makes toward the protection of mucosal surfaces against influenza infection would have been impossible without this use of animals. The pathology and clinical signs of influenza infection in both natural and experimental hosts, the advantages and disadvantages of the most common experimental influenza infection models, and the contribution of animal models to the understanding of local and systemic immunity to influenza infection are discussed.