evaluation of responses to fluzone® in infants ≥ 6 months of age who did or did not receive fluzone® at 2 months of age

Conditions: Influenza

Summary: the study is to compare the 2 groups with respect to antibody responses to inactivated influenza vaccine. observational objectives: * to describe the percentage of participants with protective hemagglutinin (hai) antibody titers to each of the 3 vaccine antigens in both study groups following each vaccination. * to describe the hai geometric mean titer (gmts) to each of the 3 vaccine antigens in both study groups following each vaccination. * to describe the safety of the 2005-2006 pediatric formulation of fluzone® vaccine in both study groups.

this is a descriptive study that will provide preliminary comparative information about the safety and immunogenicity of fluzone® vaccine among children who were given fluzone® vaccine at 2 months of age (study grc27 nct00858468)and those who never received influenza vaccine.

Eligibility criteria:
inclusion criteria: * participant is between 6 and 10 months of age on the day of inclusion (has reached 6-month but has not reached 11-month anniversary of birth). * available for the duration of the study. * born at full term of pregnancy (≥ 36 weeks) with a birth weight ≥ 2.5 kg * parent/legal acceptable representative willing and able to provide informed consent. * parent/legal acceptable representative able to attend all scheduled visits and comply with all trial procedures. * parent/legal acceptable representative willing to permit venipuncture for purposes of collecting a blood sample. * previously enrolled in the 2-month-old group in study grc27 or approved by sponsor for enrollment as control. exclusion criteria: * reported allergy to egg proteins, chicken proteins, or any other constituent of fluzone vacccine. * previous history of influenza vaccination (group 2 subjects only). * receipt of any vaccine in the 14 days prior to enrollment. * an acute illness with or without fever (rectal temperature ≥ 38.0 °c \[or ≥100.4 °f\]) in the 72 hours preceding enrollment in the trial. * known bleeding disorder. * participation in any other interventional (e.g., vaccine, drug) clinical trial (except study grc27) within 30 days prior to enrollment, or planned participation in another interventional clinical trial prior to termination of the subject's participation in this study. * known or suspected impairment of immunologic function or receipt of immunosuppressive therapy or immunoglobulin since birth. * personal or immediate family history of congenital immune deficiency. * developmental delay, neurologic disorder, or seizure disorder. * chronic medical, congenital or developmental disorder that could interfere with trial conduct or completion. * known human immunodeficiency virus (hiv)-positive or hepatitis b surface antigen (hbsag)-positive mother. * known hiv, hepatitis b, or hepatitis c infection. * receipt of blood or blood-derived products within the past 2 months. * prior history of guillain-barré syndrome. * any condition which, in the opinion of the investigator, would pose a health risk to the subject or interfere with the evaluation of the vaccine.

Keywords: fluzone® vaccine influenza