CD8A and infectious disease: Flagellin has already been tested as an adjuvant for a novel influenza vaccine in humans [88] and in addition to its exploration as a vaccine adjuvant for a variety of infectious disease vaccines in animal models, it has been able to enhance papilloma virus-specific CD8+ T cell responses in a therapeutic cancer vaccine model [89] or CD8+ T cells associated with protective immunity in a malaria model [90].