title: Influenza vaccine antibody response and 6-month persistence in lung transplant recipients using two definitions of seroprotection.
abstract: BACKGROUND
  Lung transplant recipients are among those with the highest risk of influenza infection and complications each year. A few studies show adequate responses after influenza immunization; no studies examined the season-long protection.
  
  
  METHODS
  Influenza antibody concentrations were measured using hemagglutination inhibition assays before immunization, 2 to 4 weeks after immunization, and 6 months after immunization in 25 healthy controls and 54 lung transplant patients. Two definitions of seroprotection (40 hemagglutination units (HAU) and 160 HAU which confers about 95% protection) were used.
  
  
  RESULTS
  Influenza vaccine responses were high in both groups postimmunization (100% at 40 HAU and 60% healthy and 61% lung transplant at 160 HAU; P = 1.0; chi-square). At 6 months after immunization, seroprotection rates at 40 HAU (95% healthy and 97% lung transplant; P = 1.0) and at 160 HAU (24% healthy and 36% lung transplant; P = 0.40) were observed.
  
  
  CONCLUSIONS
  Seroprotection rates do not differ between healthy and transplant groups over 6 months when 40 HAU or 160 HAU is used. However, the seroprotection rates are disappointingly low when 160 HAU (the antibody concentration associated with 95% protection from infection) is used. Annual influenza vaccine should continue to be a high priority for lung transplant patients.
authors.affiliation: University of Wisconsin School of Pharmacy 777 Highland Avenue, Madison, WI.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Long
authors.forename: Sara L
authors.initials: SL
authors.lastname: Worzella
authors.forename: John J M
authors.initials: JJ
authors.lastname: Moran
authors.forename: Mary S
authors.initials: MS
authors.lastname: Hayney
mesh_terms: D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D053122:Influenza A Virus, H3N2 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007251:Influenza, Human / Q000097:blood / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D016040:Lung Transplantation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012621:Seasons; D013997:Time Factors; D016896:Treatment Outcome; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral; D015415:Biomarkers; D007252:Influenza Vaccines