title: Decreased T-cell responses to influenza vaccination in patients with heart failure.
abstract: OBJECTIVE
  To determine whether T-cell immune responses to influenza vaccination in patients with chronic heart failure (CHF) are less vigorous than the responses of healthy control subjects.
  
  
  METHODS
  Prospective, single-center study.
  
  
  METHODS
  University hospital and research laboratory.
  
  
  METHODS
  Eighteen adults with stable CHF receiving optimal treatment and 16 healthy control subjects.
  
  
  METHODS
  Participants were immunized with the 2006-2007 trivalent inactivated (killed) influenza vaccine during October-December of 2006.
  
  
  RESULTS
  Blood samples were taken from the participants before and 2-4 weeks after vaccination to measure antibody titers, which were measured with a hemagglutination inhibition assay, then 3-4 months after vaccination to assess T-cell responses, measured by using the trans vivo delayed-type hypersensitivity method. As part of this method, which mimics physiologic conditions, peripheral blood mononuclear cells were isolated from the blood samples. The cells were mixed with influenza vaccine antigens A/H1N1, A/H3N2, and B type and injected into the footpads of SCID mice (mice with severe combined immunodeficiency), as their resulting swelling is an index of human T-cell sensitization. Median T-cell-mediated immune responses to A/H3N2 were less vigorous in patients with CHF than in control subjects (62.5 vs 87.5 microm, unadjusted p=0.031, age-adjusted p=0.006). Median responses to A/H1N1 were not significantly different between the groups (56.3 vs 75 microm, p=0.11). Median responses to B type were also similar between the groups (62.5 vs 75 microm, p=0.47). All participants mounted an antibody response to the influenza vaccine.
  
  
  CONCLUSIONS
  Patients with CHF had reduced T-cell responses to the influenza vaccine compared with healthy control subjects, as demonstrated by a lower response to A/H3N2, the newest antigen in the 2006-2007 vaccine. However, differences in T-cell immune responses to the A/H1N1 and B type strains were not found to be significant between the two groups, which suggests that patients with CHF can mount an appropriate response to vaccine antigens to which they have been previously exposed, but less so to new antigens. These findings suggest that patients with CHF may be at increased risk for influenza infection, and clinicians may want to investigate other or additional strategies for influenza vaccination.
authors.affiliation: University of Wisconsin, Madison, 53705-2222, USA.
authors.forename: Orly
authors.initials: O
authors.lastname: Vardeny
authors.forename: John J M
authors.initials: JJ
authors.lastname: Moran
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Sweitzer
authors.forename: Maryl R
authors.initials: MR
authors.lastname: Johnson
authors.forename: Mary S
authors.initials: MS
authors.lastname: Hayney
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001681:Biological Assay; D002908:Chronic Disease; D005260:Female; D006333:Heart Failure / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D006968:Hypersensitivity, Delayed; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology*; D009981:Influenza B virus / Q000276:immunology; D007252:Influenza Vaccines / Q000276:immunology*; D008297:Male; D051379:Mice; D016513:Mice, SCID; D008875:Middle Aged; D013223:Statistics as Topic; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines