Influenza virus infection causes significant morbidity and mortality each season. The infection is particularly serious in the elderly and those with chronic cardiopulmonary conditions. Solid organ transplant recipients receiving immunosuppressive therapy may be at particularly high risk for serious influenza infection. Lung transplant patients may have an even higher risk because of their underlying pathophysiology.~Influenza prophylaxis is extremely important in the care of the transplant patient. Annual influenza immunization is recommended because protection is short-lived and the vaccine composition changes. However, the efficacy and effectiveness of this intervention is largely unproven. Not surprisingly, studies have shown that lung transplant patients have lower antibody responses than healthy individuals do. To this end, this study tests the hypothesis that the influenza vaccine-induced T cell responses will be similar in lung transplant patients and healthy individuals.~Blood will be drawn prior to and 2-4 weeks after immunization and used to measure antibody responses by hemagglutination inhibition assay.~Samples will be collected in Jan-April each season to study Trans-vivo Delayed Type Hypersensitivity (TVDTH) response.~[This substudy that was originally registered to NCT00205270 and subsequently registered to its own NCT number for the purpose of clarity in linked results]
This a sub-study of a 5-year study designed to investigate how antibody and T cell responses following influenza vaccine compare among lung transplant patients, patients waiting for lung transplantation, and healthy individuals.~This trial is designed to investigate the hypothesis that there is no difference in T Cell response to the influenza vaccine between lung transplant patients and healthy controls.