title: HIV infection Worsens Age-Associated Defects in Antibody Responses to Influenza Vaccine.
abstract: BACKGROUND
  Antibody responses to seasonal influenza vaccines are defective during older age and human immunodeficiency virus (HIV) infection. The effect of HIV on immune function in aging is relatively unknown.
  
  
  METHODS
  HIV-infected and HIV-uninfected young women (age, 19-54 years) and older women (age, >55 years) were evaluated for B-cell and T-cell responses before and 4 weeks after influenza vaccination.
  
  
  RESULTS
  Frequencies of seroprotection pre-vaccination and vaccine responsiveness (≥4-fold increase in antibody titer) were lower in HIV-infected participants than in age-matched HIV-uninfected participants. A subgroup of vaccine nonresponders were compared to responders and found to have reduced frequencies of memory B cells and antigen-specific antibody-secreting cells after vaccination. Frequencies of peripheral T-follicular helper (pTfh) cells correlated with memory B-cell function and influenza A(H1N1) antibody titers. Serologic and immunologic deficits were most frequent in older HIV-infected participants. Underlying CD4(+) T-cell immune activation and inflammation correlated negatively with antibody titers and B-cell function, which was not enhanced by exogenous interleukin 21 supplementation in HIV-infected, older vaccine nonresponders.
  
  
  CONCLUSIONS
  Immune activation associated with HIV infection and impaired pTfh function heighten deficiencies in antibody responses to influenza vaccine in older individuals. Strategies to reduce immune activation or augment pTfh function may enhance antibody responses in the aging HIV-infected population.
authors.affiliation: Department of Microbiology and Immunology.
authors.forename: Varghese K
authors.initials: VK
authors.lastname: George
authors.affiliation: Department of Microbiology and Immunology.
authors.forename: Suresh
authors.initials: S
authors.lastname: Pallikkuth
authors.affiliation: Department of Microbiology and Immunology.
authors.forename: Anita
authors.initials: A
authors.lastname: Parmigiani
authors.affiliation: Division of Infectious Diseases.
authors.forename: Maria
authors.initials: M
authors.lastname: Alcaide
authors.affiliation: AIDS Clinical Research Unit, Department of Medicine.
authors.forename: Margaret
authors.initials: M
authors.lastname: Fischl
authors.affiliation: Division of Biostatistics, Epidemiology and Public Health Department, University of Miami Miller School of Medicine, Florida.
authors.forename: Kristopher L
authors.initials: KL
authors.lastname: Arheart
authors.affiliation: Department of Microbiology and Immunology.
authors.forename: Savita
authors.initials: S
authors.lastname: Pahwa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology*; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines
keywords: CD4 T-cell immune activation; HIV infection; IL-21; aging; inflammation; memory B cells; peripheral T follicular helper cells; seasonal influenza vaccination