title: Low rate of seroconversion after vaccination with a split virion, adjuvanted pandemic H1N1 influenza vaccine in HIV-1-infected patients.
abstract: OBJECTIVE
  To determine rates of seroconversion after single vaccination with a novel split virion, inactivated, adjuvanted pandemic H1N1 influenza vaccine (A/California/7/2009) in HIV-1-infected patients (ClinicalTrials.gov Identifier: NCT01017172).
  
  
  METHODS
  Single center diagnostic study.
  
  
  METHODS
  Institutional HIV outpatient department of an urban university clinic.
  
  
  METHODS
  Adult HIV-1-infected individuals.
  
  
  METHODS
  Serum samples were taken before and 21 days after vaccination.
  
  
  METHODS
  Antibody titers determined by hemagglutination inhibition assay. Seroconversion to vaccination was defined by either an antibody titer of 1: 10 or less before and of at least 1: 40 after or at least 1: 10 before and at least four-fold increase in antibody titer 21 days after single vaccination.
  
  
  RESULTS
  One hundred and sixty patients (125 men/35 women) were analyzed. Before vaccination, 23 patients (14.4%) had a hemagglutination inhibition assay titer of at least 1: 40. A median of 22 +/- 3 days after vaccination, 110 (69%) patients seroconverted. Seroconverters were younger (45.1 +/- 10.0 vs. 48.8 +/- 11.3 years; P = 0.04), had a higher CD4 cell count (532 +/- 227 vs. 475 +/- 281 cells/microl; P = 0.03) and were more likely to have received a previous H5N1 vaccination in 2009 (25 vs. 8%; P = 0.02) when compared to nonresponders. No other significant differences were found comparing the two groups (prevaccination hemagglutination inhibition assay titer of > or =1: 40, AIDS, HAART, HIV RNA PCR <50 copies/ml or CD4 nadir, CD4 and CD8 percentage, sex, BMI, chronic hepatitis B or C).
  
  
  CONCLUSIONS
  Seroconversion after one dose of a split virion, inactivated, adjuvanted pandemic H1N1 influenza vaccine of HIV-infected patients was 69%. Studies to investigate whether a second dose of the vaccine will increase seroconversion rate are needed.
authors.affiliation: HIVCENTER, Frankfurt, Germany. markus.bickel@hivcenter.de <markus.bickel@hivcenter.de>
authors.forename: Markus
authors.initials: M
authors.lastname: Bickel
authors.forename: Imke
authors.initials: I
authors.lastname: Wieters
authors.forename: Pavel
authors.initials: P
authors.lastname: Khaykin
authors.forename: Gabi
authors.initials: G
authors.lastname: Nisius
authors.forename: Annette
authors.initials: A
authors.lastname: Haberl
authors.forename: Christoph
authors.initials: C
authors.lastname: Stephan
authors.forename: Nils
authors.initials: N
authors.lastname: Von Hentig
authors.forename: Eva
authors.initials: E
authors.lastname: Herrmann
authors.forename: Hans W
authors.initials: HW
authors.lastname: Doerr
authors.forename: Hans R
authors.initials: HR
authors.lastname: Brodt
authors.forename: Regina
authors.initials: R
authors.lastname: Allwinn
mesh_terms: D000367:Age Factors; D000914:Antibodies, Viral / Q000097:blood*; D018791:CD4 Lymphocyte Count; D005260:Female; D005858:Germany / Q000453:epidemiology; D015497:HIV-1; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D014771:Virion / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines