This study will evaluate the safety and immunogenicity of one dose of H7N9 pandemic live attenuated influenza vaccine (H7N9 pLAIV) followed by AS03-adjuvanted H7N9 pandemic inactivated influenza vaccine (H7N9 pIIV).~This study will enroll healthy adults who will choose which study group to join. Participants in Group 1 will receive one dose of H7N9 pLAIV in an inpatient setting at study entry (Day 0). They will remain in an isolation unit through at least Day 9. They will also receive one dose of AS03-adjuvanted H7N9 pIIV on Day 84.~Participants in Group 2 will receive one dose of AS03-adjuvanted H7N9 pIIV at study entry (Day 0) and a second dose of AS03-adjuvanted H7N9 pIIV at Day 84. Participants in Group 3 will receive one dose of AS03-adjuvanted H7N9 pIIV at study entry (Day 0).~All participants will attend multiple study visits through Day 264. Study visits may include blood collection, physical examinations, and nasal wash and nasal wick procedures.~These three groups will be compared to two historical control groups who received one dose of H7N9 pLAIV at study entry (Day 0), one dose of H7N9 pLAIV at Day 28, and one dose of unadjuvanted H7N9 pIIV at Day 84.
The purpose of this study is to evaluate the safety and immunogenicity of one dose of H7N9 pandemic live attenuated influenza vaccine (H7N9 pLAIV) followed by AS03-adjuvanted H7N9 pandemic inactivated influenza vaccine (H7N9 pIIV).