H7N9 avian influenza (AI) viruses have been responsible for a recent outbreak of illness in humans in China, which was associated with severe respiratory illnesses resulting in acute respiratory distress syndrome (ARDS) and intensive care unit (ICU) admissions. The purpose of this study is to evaluate the safety, infectivity, and immunogenicity of a live attenuated H7N9 A/Anhui/13 cold adapted (ca) influenza virus vaccine followed by a boost with an inactivated subvirion H7N9 vaccine at varying intervals.~This study will enroll participants into five cohorts. Participants in Cohorts 1, 2, 3, and 4 will be admitted to an isolation unit on Study Day -2. On Study Day 0, participants will receive one dose of the H7N9 A/Anhui/13 ca influenza virus vaccine via a nose spray device. While in the isolation unit, participants will undergo a physical examination and nasal wash each day, and a blood collection on select days. Participants will remain in the isolation unit for at least 9 days after receiving the vaccine, but possibly longer, depending on their test results.~Participants in Cohorts 1 and 2 will return to the isolation unit 4 to 8 weeks after receiving the first vaccine (at approximately Day 28). They will receive the second dose of the H7N9 A/Anhui/13 ca influenza virus vaccine and repeat all of the same procedures that occurred after the first vaccination.~Participants will then receive one dose of the inactivated subvirion H7N9 vaccine 1 month (Cohort 1) or 2 months (Cohort 2) after receiving the second vaccine.~Participants in Cohorts 3 and 4 will receive the inactivated subvirion H7N9 vaccine either 1 month (Cohort 4) or 2 months (Cohort 3) after receiving one dose of the live attenuated vaccine. For Cohorts 1-4, participants study visits will occur 7, 14, 28, and 90 days after receiving the vaccine and will include a medical history review, physical examination, and blood collection at select visits.~Participants in Cohort 5 will receive one dose of the inactivated subvirion H7N9 vaccine at Day 0 and one dose at Day 28. Study visits will occur on Days 0, 7, 28, 35, 42, 56, and 118, and will include blood collections and physical examinations. Participants in Cohort 5 will not be admitted to the isolation unit.
H7N9 viruses have caused a recent outbreak of severe illness in humans in China. The purpose of this study is to evaluate the safety and immune response of an H7N9 A/Anhui/13 ca influenza virus vaccine followed by an inactivated subvirion H7N9 vaccine at varying intervals.