title: Immunogenicity of low-dose MF59-adjuvanted 2009 influenza A/H1N1 vaccine in dialysis patients.
abstract: BACKGROUND
  In response to the pandemic 2009 A/H1N1 virus, monovalent MF59-adjuvanted vaccines were prepared. Recently, single 3.75-μg doses of MF59-adjuvanted vaccines have shown good immunogenicity in young adults. However, the immunogenicity of these vaccines has not been evaluated in dialysis patients.
  
  
  METHODS
  Dialysis patients received a single 3.75-μg dose of MF59-adjuvanted vaccine by intramuscular injection. For immunogenicity assays, serum samples were obtained before vaccination and 28 days after vaccination. All sera were tested by hemagglutination inhibition assays.
  
  
  RESULTS
  Overall, 48 hemodialysis (HD) patients and 34 peritoneal dialysis (PD) patients were included in immunogenicity analysis. In HD patients, geometric mean titers (GMTs) were significantly increased compared with baseline GMTs in both young (aged 18-60 years) and elderly (aged ≥ 60 years) patients (51.2 ± 51.4 vs. 14.1 ± 20.7 in young patients, P = 0.012; 37.9 ± 73.9 vs. 6.8 ± 8.0 in elderly patients, P = 0.018, respectively). The rates of seroprotection and seroconversion were 27.6 and 17.2 % in young patients and 31.6 and 26.3 % in elderly patients, respectively. Among PD patients, GMTs were increased only in young patients (39.8 ± 51.4 vs. 6.8 ± 5.0, P = 0.001). The rates of seroprotection and seroconversion were 36.0 and 36.0 % in young patients and 11.1 and 0.0 % in elderly patients, respectively.
  
  
  CONCLUSIONS
  A single 3.75-μg dose of MF59-adjuvanted vaccine was suboptimal to elicit protective antibody response in dialysis patients. Antibody responses against vaccine were compromised especially in elderly PD patients. Trials of different vaccination protocols such as a two-dose schedule or a higher hemagglutinin antigen dose of MF59-adjuvanted vaccine are necessary for improving antibody response in dialysis patients.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Pusan National University School of Medicine, Beomeo-ri, Mulgeum-eup, Gyeongsangnam-do, Yangsan, 626-770, South Korea.
authors.forename: Jungmin
authors.initials: J
authors.lastname: Son
authors.forename: Soo Bong
authors.initials: SB
authors.lastname: Lee
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Lee
authors.forename: Il Young
authors.initials: IY
authors.lastname: Kim
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Sun Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Sang Heon
authors.initials: SH
authors.lastname: Song
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Seong
authors.forename: Ihm Soo
authors.initials: IS
authors.lastname: Kwak
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000368:Aged; D000375:Aging / Q000276:immunology; D000914:Antibodies, Viral / Q000032:analysis; D023381:Endpoint Determination; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007273:Injections, Intramuscular; D007676:Kidney Failure, Chronic / Q000276:immunology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D011136:Polysorbates / Q000494:pharmacology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D006435:Renal Dialysis; D013185:Squalene / Q000494:pharmacology*; D014611:Vaccination
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007252:Influenza Vaccines; C089950:MF59 oil emulsion; D011136:Polysorbates; D013185:Squalene