A Phase I Study Priming With an Inactivated A/H7N9 Influenza Virus Vaccine With or Without MF59 Adjuvant Followed by Live Attenuated A/H7N9 Influenza Virus Vaccine

A phase I prospective, randomized study in healthy adult subjects at a single center. Adult subjects age 18 to 47 years and meeting all enrollment criteria will choose to participate as subjects who receive inactivated vaccine followed by a live vaccine boost at 4 weeks (Group 1), 12 weeks (Group 2), or 24 weeks (Group 3), or to be in an observational group (Group 4) which will not be scheduled for a booster dose but may serve as a roll-over group for subjects who withdraw prior to the second vaccination but agree to remain in follow-up. A fifth group will receive two intramuscular doses of adjuvanted H7N9 pIIV separated by four weeks. The primary objectives of this study are to (1) assess the safety of H7N9 pLAIV administered to individuals who have previously received MF59-adjuvanted or unadjuvanted H7N9 pIIV, (2) evaluate the ability of a single dose of unadjuvanted H7N9 pIIV to prime for enhanced immunogenicity (booster response) to subsequent administration of antigenically-matched H7N9 pLAIV vaccine, and to (3) evaluate the ability of a single dose of MF59-adjuvanted H7N9 pIIV to prime for enhanced immunogenicity (booster response) to subsequent administration of antigenically-matched H7N9 pLAIV vaccine.