Bone Marrow and Peripheral Blood Immune Responses Study

The purpose of this study is to evaluate the immune response of the killed flu vaccine in healthy subjects. Participants in this study are considered to be healthy volunteers. Influenza ("Flu") infection carries a risk of serious illness. This is an open label and single arm observational study designed to assess the humoral response to influenza vaccination and the longevity of humoral immunity to influenza vaccination in healthy adults. Enrolled subjects will receive licensed seasonal inactivated influenza vaccine (administered as a part of the study). Participants will donate serial samples of blood and bone marrow aspirate for immunology monitoring. Repeated measurements of humoral immunity will be obtained at 7 days, 28 days, 90 days and at one year post vaccination to assess the magnitude, clonal diversity and persistence of B-cell responses to influenza vaccination.