Safety and Efficacy of an H1N1 Influenza Vaccine in People With Asthma

The purpose of this study is to assess the safety and the body's immune response (body's defense against disease) to an experimental H1N1 influenza vaccine in people with asthma. The study will enroll 350, and possibly up to 400 healthy adults ages 12 and older with mild, moderate, or severe asthma. Participants will be randomly assigned to 1 of 2 possible vaccine groups: group 1 will receive 15 mcg of H1N1 vaccine; group 2 will receive 30 mcg of H1N1 vaccine given as two 15 mcg injections. Both groups will receive vaccine injections on days 0 and 21. Study procedures include: medical history, physical exam, spirometry, maintaining a memory aid and, and blood sample collection. Participants will be involved in study related procedures for approximately 7 months.