CD8A and influenza: Moreover, two conserved protein fragments plus a string of CD8+ T cell epitopes from the influenza virus, representing promising influenza vaccine targets [43-45,62], were expressed at the surface of Salmonella. Whether Hbp-mediated surface expression of abovementioned antigens on live cells or derived outer membrane vesicles and bacterial ghosts will lead to successful vaccination strategies against TB, chlamydia and influenza will be investigated in future challenge studies.