This is a Phase II open-label study in approximately 240 (up to 400) healthy males and non-pregnant females, 6 months to 17 years old, inclusive. This study is designed to assess the safety, reactogenicity, and immunogenicity of two doses administered intramuscularly approximately 21 days apart of an unadjuvanted subvirion monovalent inactivated influenza H3N2 variant (H3N2v) vaccine (MIV) manufactured by sanofi pasteur. Subjects will be stratified by age (approximately 120 (up to 200) subjects 6-35 months old, approximately 60 (up to 100) subjects 3-8 years old, and approximately 60 (up to 100) subjects 9-17 years old). Subjects in the 6-35 months old cohort will be randomized to receive either two doses of H3N2v MIV, administered intramuscularly as 7.5 micrograms (mcg) of hemagglutinin (HA)/0.25 milliliter (mL) dose (approximately 60 (up to 100) subjects), approximately 21 days apart, or two doses of H3N2v MIV, administered intramuscularly as 15mcg HA/0.5mL dose (approximately 60 (up to 100) subjects), approximately 21 days apart. All subjects in the 3-8 years old cohort and 9-17 years old cohort will receive two doses of H3N2v MIV, delivered intramuscularly as 15mcg HA/0.5mL dose, approximately 21 days apart. Subjects may receive licensed seasonal influenza vaccine prior to (>2 weeks if given the inactivated vaccine or >4 weeks if given the live, attenuated vaccine) the first H3N2v vaccination. Alternatively, subjects may receive licensed seasonal influenza vaccine at any time after completion of Visit 05 or following an early termination visit. Safety will be measured by the occurrence of solicited injection site and systemic reactogenicity from the time of each H3N2v vaccination through 7 days after each H3N2v vaccination. Unsolicited non-serious adverse events (AEs) will be collected from the time of the H3N2V vaccination (Day 0 (Visit 01)) through approximately 21 days after the last H3N2v vaccination (approximately Day 42 (Visit 05) for subjects who receive two H3N2v vaccinations; approximately Day 21 (Visit 03) for subjects who receive only one H3N2v vaccination). After approximately 21 days after the last H3N2v vaccination, non-serious AEs will be limited to new-onset chronic medical conditions, which will be documented through approximately 7 months after the first H3N2v vaccination (Visit 08). Serious adverse events (SAEs) will be collected from the time of the first H3N2v vaccination (Day 0 (Visit 01)) through approximately 7 months after the first H3N2v vaccination (Visit 08). Immunogenicity testing will include performing hemagglutination inhibition (HAI) and neutralizing (Neut) antibody assays on serum obtained prior to each H3N2v vaccination (Day 0 (Visit 01) and approximately Day 21 (Visit03)) and approximately 21 days after the second H3N2v vaccination (Visit 05).
This is a Phase II open-label study in approximately 240, and up to 400, healthy males and non-pregnant females, aged 6 months to 17 years. This study is designed to assess the safety, reactogenicity, and immunogenicity of two doses administered intramuscularly approximately 21 days apart of an unadjuvanted subvirion monovalent inactivated influenza H3N2v vaccine manufactured by sanofi pasteur. Subjects will be stratified by age (approximately 60-100 subjects 6-35 months old, approximately 60-100 subjects 3-8 years old and approximately 60-100 subjects 9-17 years old) to receive 2 doses of vaccine, administered intramuscularly as 15mcg HA/0.5mL dose, approximately 21 days apart. In addition, approximately 60-100 subjects 6-35 months old will receive 2 doses of vaccine, administered intramuscularly as 7.5mcg HA/0.5mL dose, approximately 21 days apart. The duration of the study for each subject will be approximately 7 months.