title: Safety and immunogenicity of a vero cell culture-derived whole-virus influenza A(H5N1) vaccine in a pediatric population.
abstract: BACKGROUND
  Children are highly vulnerable to infection with novel influenza viruses. It is essential to develop candidate pandemic influenza vaccines that are safe and effective in the pediatric population.
  
  
  METHODS
  Infants and children aged 6-35 months and 3-8 years, respectively, were randomized to receive 2 immunizations with a 7.5-µg or 3.75-µg hemagglutinin (HA) dose of a nonadjuvanted whole-virus A/Vietnam(H5N1) vaccine; adolescents aged 9-17 years received a 7.5-µg dose only. A subset of participants received a booster immunization with an A/Indonesia(H5N1) vaccine approximately 1 year later. HA and neuraminidase antibody responses were assessed.
  
  
  RESULTS
  Vaccination was safe and well tolerated; adverse reactions were transient and predominantly mild. Two immunizations with the 7.5-µg dose of A/Vietnam vaccine induced virus microneutralization (MN) titers of ≥1:20 against the A/Vietnam strain in 68.8%-85.4% of participants in the different age groups. After the booster, 93.1%-100% of participants achieved MN titers of ≥1:20 against the A/Vietnam and A/Indonesia strains. Neuraminidase-inhibiting antibodies were induced in ≥90% of participants after 2 immunizations with the 7.5 µg A/Vietnam vaccine and in 100% of participants after the booster.
  
  
  CONCLUSIONS
  A whole-virus influenza A(H5N1) vaccine is suitable for prepandemic or pandemic immunization in a pediatric population.
  
  
  BACKGROUND
  NCT01052402.
authors.affiliation: Vaccine Research and Development.
authors.forename: Maikel V W
authors.initials: MV
authors.lastname: van der Velden
authors.forename: Richard
authors.initials: R
authors.lastname: Fritz
authors.forename: Eva Maria
authors.initials: EM
authors.lastname: Pöllabauer
authors.forename: Daniel
authors.initials: D
authors.lastname: Portsmouth
authors.forename: M Keith
authors.initials: MK
authors.lastname: Howard
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Kreil
authors.forename: Thomas
authors.initials: T
authors.lastname: Dvorak
authors.forename: Sandor
authors.initials: S
authors.lastname: Fritsch
authors.forename: Timo
authors.initials: T
authors.lastname: Vesikari
authors.forename: Javier
authors.initials: J
authors.lastname: Diez-Domingo
authors.forename: Peter
authors.initials: P
authors.lastname: Richmond
authors.forename: Bee Wah
authors.initials: BW
authors.lastname: Lee
authors.forename: Otfried
authors.initials: O
authors.lastname: Kistner
authors.forename: Hartmut J
authors.initials: HJ
authors.lastname: Ehrlich
authors.forename: P Noel
authors.initials: PN
authors.lastname: Barrett
authors.forename: Gerald
authors.initials: G
authors.lastname: Aichinger
mesh_terms: D000293:Adolescent; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood / Q000276:immunology; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D002522:Chlorocebus aethiops; D005260:Female; D006801:Humans; D007223:Infant; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D008297:Male; D014709:Vero Cells
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007252:Influenza Vaccines
keywords: HA; NA; Vero; cell culture; children; heterosubtypic immunity; immunological priming; neuraminidase; pediatric; whole-virus H5N1 vaccine