title: The immunogenicity of a novel A (H1N1) vaccine in HIV-infected children.
abstract: BACKGROUND
  In October 2009, the United Kingdom Department of Health recommended vaccination of high-risk groups, including children with HIV, with a novel, oil-in-water AS03(B) adjuvanted Influenza A (H1N1) vaccine (Pandemrix). There were no published data available regarding the immunogenicity of this vaccine in such children.
  
  
  OBJECTIVE
  This study evaluated the immunogenicity of the adjuvanted Influenza A (H1N1) vaccine in HIV-infected children immunised according to national recommendations and assessed the impact of vaccination on individual CD4 counts and HIV viral loads.
  
  
  METHODS
  HIV-infected children attending outpatient appointments between 01 November and 31 December 2009 were offered two doses of H1N1 vaccine three weeks apart and a blood test before and 3 weeks after the second dose of vaccine. Serum antibody responses were determined by a haemagglutination inhibition (HAI) assay using standard methods.
  
  
  RESULTS
  Of the 39 children recruited for vaccination, 31 (median age 11.2, range 3.0-17.9 years) received both doses of vaccine and provided pre- and post-vaccination blood samples. Eight children (26%) had baseline HAI titres ≥ 1:32. After vaccination, 29 children (94%, 95% CI, 78.6-99.2%) had HAI titres ≥ 1:32 (seroprotection), of whom 27 (87.1%, 95% CI, 70.1-96.4%) had also had a four-fold rise in titres (seroconversion). In the univariate analysis, post-vaccination geometric mean titres (GMTs) were higher among the 21 children receiving highly active anti-retroviral therapy compared with the 10 treatment-naïve children (GMT 406 [95% CI 218-757] vs. 128 [49-336]; P=0.035), but this was no longer statistically significant when adjusted for prevaccine GMTs. There was no significant impact of vaccination on CD4+ T cell count or HIV viral load.
  
  
  CONCLUSIONS
  The AS03(B)-adjuvanted pandemic Influenza A (H1N1) vaccine is highly immunogenic and appears to be safe in HIV-infected children.
authors: Vaccine Institute, St. George's, University of London, London, United Kingdom. iokike@sgul.ac.uk
authors: Ifeanyichukwu O
authors: IO
authors: Okike
authors: Chee
authors: C
authors: Yung
authors: Shamez
authors: S
authors: Ladhani
authors: Clarissa
authors: C
authors: Oeser
authors: Aisleen
authors: A
authors: Bennett
authors: Katja
authors: K
authors: Doerholt
authors: Sharon
authors: S
authors: Storey
authors: Sheila
authors: S
authors: Donaghy
authors: Nigel
authors: N
authors: Butter
authors: Katja
authors: K
authors: Hoschler
authors: Liz
authors: L
authors: Sheasby
authors: Paul T
authors: PT
authors: Heath
authors: Elizabeth
authors: E
authors: Miller
mesh_terms: D000276:Adjuvants, Immunologic; D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D004338:Drug Combinations; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000302:isolation & purification; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D008297:Male; D011136:Polysorbates / Q000008:administration & dosage / Q000009:adverse effects; D013185:Squalene / Q000008:administration & dosage / Q000009:adverse effects; D006113:United Kingdom; D014611:Vaccination / Q000379:methods; D019562:Viral Load; D024502:alpha-Tocopherol / Q000008:administration & dosage / Q000009:adverse effects
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D004338:Drug Combinations; D007252:Influenza Vaccines; D011136:Polysorbates; C556153:pandemrix; D013185:Squalene; C550253:AS03 adjuvant; D024502:alpha-Tocopherol