title: Quantitative and qualitative anamnestic immune responses to pneumococcal conjugate vaccine in HIV-infected and HIV-uninfected children 5 years after vaccination.
abstract: BACKGROUND
  Administration of pneumococcal conjugate vaccine (PCV) to HIV-infected children during infancy confers limited long-term protection in the absence of antiretroviral therapy. The objective of the present study was to determine the immune responses to PCV at 5 years of age in HIV-infected and HIV-uninfected children who had been primed with vaccine during infancy (i.e., previous vaccinees) and in those receiving their first dose of vaccine (i.e., control subjects).
  
  
  METHODS
  Serotype-specific antibodies were quantified by enzyme immunoassay, and antibody functionality to serotypes 6B, 9V, and 19F were evaluated using an opsonophagocytic killing assay 1 month after vaccination.
  
  
  RESULTS
  Of the HIV-infected children, 19.7% were receiving antiretroviral therapy, and 40.5% had a CD4(+) cell percentage <15%. Geometric mean concentrations of antibody and the proportion with a concentration 0.35 microg/mL after vaccination were greater among HIV-uninfected children than among HIV-infected children for both previous vaccinees and control subjects. Antibody concentrations after vaccination were lower for 3 of 7 serotypes among HIV-infected previous vaccinees than among control subjects. Detectable opsonophagocytic activity to all studied serotypes was lower among HIV-infected than among HIV-uninfected previous vaccinees and control subjects. Postvaccination antibody-mediated killing activity as determined by the opsonophagocytic killing assay was enhanced in control subjects compared with previous vaccinees among HIV-uninfected children.
  
  
  CONCLUSIONS
  HIV-infected vaccinees experience a partial loss of anamnestic responses to PCV. The optimal timing and frequency of booster vaccination as well as the responses to them among HIV-infected children need to be determined.
authors.affiliation: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand/Medical Research Council, Johannesburg, South Africa. madhis@hivsa.com
authors.forename: Shabir A
authors.initials: SA
authors.lastname: Madhi
authors.forename: Keith P
authors.initials: KP
authors.lastname: Klugman
authors.forename: Locadiah
authors.initials: L
authors.lastname: Kuwanda
authors.forename: Clare
authors.initials: C
authors.lastname: Cutland
authors.forename: Helena
authors.initials: H
authors.lastname: Käyhty
authors.forename: Peter
authors.initials: P
authors.lastname: Adrian
mesh_terms: D019380:Anti-HIV Agents / Q000627:therapeutic use; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D002675:Child, Preschool; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology*; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007115:Immunization Schedule; D008297:Male; D011008:Pneumococcal Infections / Q000276:immunology*; D022242:Pneumococcal Vaccines / Q000276:immunology*; D014611:Vaccination / Q000592:standards*
chemical_list: D019380:Anti-HIV Agents; D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines