Development of Childhood Anti-Influenza Immunity
Condition: Influenza; Influenza Immunisation
MeSH terms: Influenza, Human
Study type: Interventional
Phase: Phase 4

Summary: 
      This study is a prospective surveillance of the immune response to seasonal vaccination in
      healthy children. The study will enroll a total of approximately 220 subjects. 140 children
      will be vaccinated with inactivated influenza vaccine (IIV) and will be divided into 4 age
      cohorts: 20 children between 6-12 months of age, 60 children greater than 12 months of age
      and born after 2009, 30 children with a birth date between 2006 and 2009, and 30 children
      with a birth date between 2003 and 2006. 80 children presenting with natural influenza
      infection prior to receipt of influenza vaccination also will be divided into 4 age cohorts:
      20 children between 3-12 months of age, 20 children greater than 12 months of age with a
      birth date after 2009, 20 children with a birth date between 2006 and 2009, and 20 children
      with a birth date between 2003 and 2006. Influenza vaccines will be administered using
      age-appropriate guidelines in all years of the study: Fluzone 0.25 mL administered
      intramuscularly to children between 6 and 35 months of age and 0.5 mL to children 36 months
      of age and older. Subjects will be seen at one domestic site and their participation duration
      is 2 influenza seasons plus 1 optional season. The primary hypothesis being tested in this
      study is that there will be differences in the specificity, magnitude and functionality of
      CD4 T cell and B cell reactivity in a cohort of children depending on early childhood
      exposures. The primary objective of this study is to evaluate the relationship between
      influenza virus exposure, infection and vaccine history, and CD4 T cell reactivity in a
      cohort of children with well documented influenza exposures.
    

Detailed description: 
      This study is a prospective surveillance of the immune response to seasonal vaccination in
      healthy children. The study will enroll a total of approximately 220 subjects. 140 children
      will be vaccinated with inactivated influenza vaccine (IIV) and will be divided into 4 age
      cohorts: 20 children between 6-12 months of age, 60 children greater than 12 months of age
      and born after 2009, 30 children with a birth date between 2006 and 2009, and 30 children
      with a birth date between 2003 and 2006. 80 children presenting with natural influenza
      infection prior to receipt of influenza vaccination also will be divided into 4 age cohorts:
      20 children between 3-12 months of age, 20 children greater than 12 months of age with a
      birth date after 2009, 20 children with a birth date between 2006 and 2009, and 20 children
      with a birth date between 2003 and 2006. Influenza vaccines will be administered using
      age-appropriate guidelines in all years of the study: Fluzone 0.25 mL administered
      intramuscularly to children between 6 and 35 months of age and 0.5 mL to children 36 months
      of age and older. Subjects will be seen at one domestic site and their participation duration
      is 2 influenza seasons plus 1 optional season. The primary hypothesis being tested in this
      study is that there will be differences in the specificity, magnitude and functionality of
      CD4 T cell and B cell reactivity in a cohort of children depending on early childhood
      exposures. The primary objective of this study is to evaluate the relationship between
      influenza virus exposure, infection and vaccine history, and CD4 T cell reactivity in a
      cohort of children with well documented influenza exposures.
    

Intervention name(s): Influenza Virus Quadrivalent Inactivated Vaccine
Intervention type(s): Biological
Intervention description(s): A seasonal quadrivalent inactivated influenza vaccine (IIV4), prepared from influenza viruses propagated in embryonated chicken eggs, protecting against 2 influenza A subtypes (H1N1 and H3N3) and 2 influenza B subtypes (B Yamata lineage B Victoria lineage).
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: B Cell; CD4 T Cell; Children; Influenza Vaccination; Protective Immunity