H7N9 Boost in Healthy Adults

This is a Phase II, open-label study in up to 50 males and non-pregnant females, 19 to 50 years old, inclusive, who are in good health and meet all entry criteria. The study is designed to assess the safety, reactogenicity, and immunogenicity of a single dose of a monovalent inactivated influenza A/H7N9 virus vaccine (45 mcg of HA/0.75 mL) manufactured by Sanofi Pasteur administered to healthy adults who previously received two doses of monovalent inactivated influenza A/H7N7 virus vaccine manufactured by Sanofi Pasteur or one or two doses of placebo in Protocol 07-0023. All subjects will receive a single dose of the inactivated influenza A/H7N9 vaccine delivered intramuscularly. Reactogenicity will be measured by the occurrence of solicited injection site and systemic reactions from the time of the study vaccination Day 1/Visit 01 through 8 days after the study vaccination. Unsolicited non-serious adverse events (AEs) will be collected from the time of the study vaccination through roughly 28 days after the study vaccination. Serious adverse events (SAEs) and new-onset chronic medical conditions will be collected from the time of the study vaccination through roughly 6 months after the study vaccination. Immunogenicity testing against A/H7N9 and A/H7N7 antigens will include performing hemagglutination inhibition (HAI) and neutralizing (Neut) antibody assays on serum obtained immediately prior to the study vaccination, and roughly 8 and 28 days after the study vaccination. An additional 60 mL of venous blood will be drawn immediately prior to the study vaccination, and roughly 8 and 28 days after the study vaccination for exploratory cellular immunology assays. The duration of this study for each subject will be roughly 6 months. The primary objectives are 1. to assess the safety and reactogenicity of a single dose monovalent inactivated influenza A/H7N9 virus vaccine in individuals who previously received two intramuscular doses of a monovalent inactivated influenza A/H7N7 virus vaccine or are A/H7 vaccine-naïve. 2. To assess the serum hemagglutination inhibition (HAI) antibody responses against A/H7N9 roughly 28 days following receipt of a single dose of a monovalent inactivated influenza A/H7N9 virus vaccine in individuals who previously received two intramuscular doses of a monovalent inactivated influenza A/H7N7 virus vaccine or are A/H7 vaccine-naïve. The secondary objectives are 1. To assess study-vaccine related unsolicited non-serious adverse events following receipt of one dose of a monovalent inactivated influenza A/H7N9 virus vaccine in individuals who previously received two intramuscular doses of a monovalent inactivated influenza A/H7N7 virus vaccine or are A/H7 vaccine-naïve. 2. To assess new-onset chronic medical conditions following receipt of one dose of a monovalent inactivated influenza A/H7N9 virus vaccine in individuals who previously received two intramuscular doses of a monovalent inactivated influenza A/H7N7 virus vaccine or are A/H7 vaccine-naïve.3) To assess the serum HAI antibody responses against A/H7N9 at baseline and about 8 days following receipt of a single dose of a monovalent inactivated influenza A/H7N9 virus vaccine in individuals who previously received two intramuscular doses of a monovalent inactivated influenza A/H7N7 virus vaccine or are A/H7 vaccine-naïve. 4. To assess the serum neutralizing (Neut) antibody responses against A/H7N9 at baseline and roughly 8 and 28 days following receipt of a one dose of a monovalent inactivated influenza A/H7N7 virus vaccine or are A/H7 vaccine-naïve.