The purpose of this study is to evaluate the safety, any adverse events or side effects, and the body's immune response to an experimental flu vaccine [Inactivated Influenza A/H7N7 Vaccine] being given in increasing doses. Researchers will try to find the smallest dose of flu vaccine needed to cause antibody responses against the flu virus in both single and repeat doses. The study will enroll 125 healthy adults ranging in age from 18 to 40 years old. Subjects will be given 2 doses of the vaccine 28 days apart. Study procedures will include obtaining a medical history, physical exam, blood sample collections, and use of patient memory aids. The volunteers will be in the study for about 7 months.