title: Immune response after one or two doses of pandemic influenza A (H1N1) monovalent, AS03-adjuvanted vaccine in HIV infected adults.
abstract: BACKGROUND
  Continued research is needed to evaluate and improve the immunogenicity of influenza vaccines in HIV infected patients. We aimed to determine the antibody responses after one or two doses of the AS03-adjuvanted pandemic influenza A (H1N1) vaccine in HIV infected patients.
  
  
  METHODS
  Following the influenza season 2009/2010, 219 HIV infected patients were included and divided into three groups depending on whether they received none (n=60), one (n=31) or two (n=128) doses of pandemic influenza A (H1N1) vaccine. At inclusion, antibody titers for all patients were analyzed and compared to pre-pandemic antibody titers analyzed from serum samples in a local storage facility.
  
  
  RESULTS
  4-9 months after a single immunization, we found a seroprotection rate of 77.4% and seroconversion rate of 67.7%. After two immunizations the rates increased significantly to seroprotection rate of 97.7% and seroconversion rate of 86.7%.
  
  
  CONCLUSIONS
  A single dose of AS03-adjuvanted pandemic influenza A (H1N1) vaccine created an adequate immune response in HIV infected patients lasting as long as 4-9 months. Two doses improved the immunogenicity further.
authors.affiliation: Department for Infectious Diseases, Hvidovre Hospital, University Hospital of Copenhagen, Copenhagen, Denmark. allan@bybeck.dk
authors.forename: Allan Bybeck
authors.initials: AB
authors.lastname: Nielsen
authors.forename: Henriette Schjønning
authors.initials: HS
authors.lastname: Nielsen
authors.forename: Lars
authors.initials: L
authors.lastname: Nielsen
authors.forename: Søren
authors.initials: S
authors.lastname: Thybo
authors.forename: Gitte
authors.initials: G
authors.lastname: Kronborg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D004338:Drug Combinations; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011136:Polysorbates / Q000008:administration & dosage*; D013185:Squalene / Q000008:administration & dosage*; D024502:alpha-Tocopherol / Q000008:administration & dosage*
chemical_list: D000914:Antibodies, Viral; D004338:Drug Combinations; D007252:Influenza Vaccines; D011136:Polysorbates; C556153:pandemrix; D013185:Squalene; C550253:AS03 adjuvant; D024502:alpha-Tocopherol