CD28 is the classical costimulatory molecule involved in T cell activation and initial priming of T cells.  However, no work has been done looking at the role of CD28 in expansion/contraction of T cells or memory generation.  We are examining the role of CD28 in these later phases of the immune response to Influenza A virus and studying the mechanisms by which CD28 controls the T cell response. 

Vaccines currently available against influenza virus use killed virus and result in the production of antiviral antibodies. Such antibodies, however, are unable to protect against emerging strains of the virus. Therefore, development of vaccines that stimulate CD8+ T cell immunity is critical. We are currently looking at different routes of administration of live influenza virus and their effect on the antiviral CD8+ T cell responses to secondary infection.