Response to Inactivated Influenza Vaccine in Lymph Tissue and Blood

This is a Phase IV study of licensed influenza vaccines with up to 50 volunteers, 20-75 years of age. Each volunteer will participate for approximately 1 week including enrollment, vaccination, and completion of sample collection. The study has a total of 3 visits. Study Procedures: Screening Visit: Procedures during this visit are: Informed consent process, assess eligibility collect relevant clinical data and obtain 10 mL of blood to ensure the FNA will be safe (acceptable CBC and PT/PTT). Visit 1: Vaccination Visit: Eligible subjects will return and have a 20 mL blood sample. Participants will receive the inactivated flu vaccine into the right anterior quadriceps. Volunteers will be monitored for at least 15 minutes after study vaccination. Visit 2: FNA Procedure: Seven days after vaccination the participant will return for another collection of 20 ml of blood and a fine needle aspiration of a right inguinal lymph node under ultrasound guidance by a trained pathologist.