The study will require a 10-ml sample of whole blood to be drawn from each participant prior to the dose of the seasonal influenza vaccine and at 3 weeks after the vaccine dose and at 3 months after the vaccine dose. No additional samples are envisioned. Serum will be separated and will frozen and stored in the Clinical Trials Unit until all patient samples have been obtained. At that time the antibody levels to the vaccine antigens will be measured.