title: Antibody persistence and response to 2010-2011 trivalent influenza vaccine one year after a single dose of 2009 AS03-adjuvanted pandemic H1N1 vaccine in children.
abstract: BACKGROUND
  In 2009, several countries used the ASO3-adjuvanted pandemic A/H1N1 vaccine. We assessed the persistence of antibody and the priming induced by a single paediatric dose of this vaccine in children.
  
  
  METHODS
  Children aged 15-120 months vaccinated one year before with the ASO3-adjuvanted monovalent pandemic vaccine were tested for the presence of antibody against 2010-2011 TIV components (A/California/7/2009(H1N1), A/Wisconsin/15/2009 (H3N2 A/Perth/16/2009-like) and B/Brisbane/60/2008) before and 21-28 days after each dose of 2010-2011 TIV. Hemagglutination-inhibition (HAI) assay was used. Children received one or two doses of 2010-2011 TIV at 21-28 days interval in relation with their previous immunization status.
  
  
  RESULTS
  The results of 128 children were included in the ATP analysis. Before the 2010-2011 TIV administration, 46% of children showed sero-protection to the A/California/7/2009(H1N1) strain (HAI titre ≥40) with lower rates of sero-protection to the H3N2A/Perth/16/2009 (37%) and B/Brisbane/60/2008 (19%). After the first dose of 2010-2011 TIV, 98%, 75%, and 57% of vaccinees attained a sero-protective titre to A/California/7/2009(H1N1), A/Perth/16/2009(H3N2), and B/Brisbane/60/2008 strain, respectively. The youngest age group showed significantly lower antibody response to the influenza B component compared to the older age groups after the first dose of vaccine. Among vaccinees who received the second dose of TIV, 96% and 87% had a sero-protective titre to H3N2A/Perth/16/2009 and B/Brisbane/60/2008, respectively. The 2010-2011 TIV was well tolerated.
  
  
  CONCLUSIONS
  We found substantial persistence of antibody to the A/California/7/2009 strain one year after a single paediatric dose of AS03-adjuvanted pandemic vaccine and a seroprotective level of antibody to this strain in virtually all children who received one year later a single dose of the 2010-2011 TIV. In contrast, two doses of the 2010-2011 TIV were necessary to induce an adequate immune response to the A/Perth/16/2009(H3N2) and B/Brisbane/60/2008 strains in children previously naïve to seasonal vaccine.
authors: Quebec Public Health Institute, Canada. vladimir.gilca@ssss.gouv.qc.ca
authors: Vladimir
authors: V
authors: Gilca
authors: Gaston
authors: G
authors: De Serres
authors: Marie-Eve
authors: ME
authors: Hamelin
authors: Guy
authors: G
authors: Boivin
authors: Manale
authors: M
authors: Ouakki
authors: Nicole
authors: N
authors: Boulianne
authors: Chantal
authors: C
authors: Sauvageau
authors: Marc
authors: M
authors: Dionne
authors: Rodica
authors: R
authors: Gilca
authors: Danuta
authors: D
authors: Skowronski
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods*; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D014611:Vaccination / Q000379:methods*
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007252:Influenza Vaccines