title: Deficient long-term response to pandemic vaccine results in an insufficient antibody response to seasonal influenza vaccination in solid organ transplant recipients.
abstract: BACKGROUND
  Little is known about the long-term antibody response to the 2009-H1N1 vaccine in solid organ transplant recipients (SOTR) and its clinical repercussion on the efficacy of following 2010-2011 influenza vaccine.
  
  
  METHODS
  We performed a multicenter prospective study in SOTR receiving one dose of the nonadjuvant 2010-2011 seasonal influenza vaccine and determined the immunological response at 5 weeks after vaccination.
  
  
  RESULTS
  One hundred SOTR were included. Long-term antibody titers to the previous vaccine were only detected in one third of the patients. Patients with baseline titers had significantly higher seroprotection for the 2009-H1N1 strain (100% vs. 73%, relative risks [RR] 1.37, 95% confidence intervals [CI] 1.19-1.57; P=0.006), for H3N2 strain (100% vs. 62.2%, RR 1.61, 95% CI 1.36-1.90; P=0.005), and for B strain (100% vs. 69%; P=0.02). The seroconversion rate in patients with baseline titers was 90.9% vs. 73% (RR 2.97, 95% CI 0.75-11.74; P=0.07) for the 2009-H1N1 strain, 92.2% vs. 62.2% (RR 5.29, 95% CI 0.8-35.7; P=0.02) for the H3N2 strain, and 58.3% vs. 69% (P=0.45) for the B strain.
  
  
  CONCLUSIONS
  SOTR response to the 2010-2011 influenza vaccine was not optimal. The response was related to baseline titers; however, most of the patients did not exhibit detectable antibodies at vaccination lacking long-term response. New strategies are necessary to improve vaccination efficacy.
authors.affiliation: Instituto de Biomedicina de Sevilla (IBiS), University Hospital Virgen del Rocio/CSIC/University of Sevilla. Unit of Infectious Diseases, Microbiology and Preventive Medicine, Sevilla, Spain.
authors.forename: Elisa
authors.initials: E
authors.lastname: Cordero
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Aydillo
authors.forename: Ana
authors.initials: A
authors.lastname: Perez-Ordoñez
authors.forename: Julian
authors.initials: J
authors.lastname: Torre-Cisneros
authors.forename: Rosario
authors.initials: R
authors.lastname: Lara
authors.forename: Carmen
authors.initials: C
authors.lastname: Segura
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Gentil
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Gomez-Bravo
authors.forename: Ernesto
authors.initials: E
authors.lastname: Lage
authors.forename: Jeronimo
authors.initials: J
authors.lastname: Pachon
authors.forename: Pilar
authors.initials: P
authors.lastname: Perez-Romero
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000276:immunology*; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology* / Q000627:therapeutic use; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D016377:Organ Transplantation; D058873:Pandemics; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines