title: Low seroconversion after one dose of AS03-adjuvanted H1N1 pandemic influenza vaccine in solid-organ transplant recipients.
abstract: BACKGROUND
  Immunocompromised individuals are more susceptible to complications produced by influenza infection. As a result, solid-organ transplant (SOT) recipients were targeted as a priority group to receive AS03-adjuvanted H1N1 influenza vaccine during 2009.
  
  
  OBJECTIVE
  To evaluate seroconversion after one dose of adjuvanted pandemic influenza H1N1 (pH1N1) vaccine in SOT recipients.
  
  
  METHODS
  Adult SOT recipients were enrolled to receive one 3.75 μg dose of adjuvanted pH1N1 vaccine. Serological status was tested using a hemagglutination inhibition assay before and two and four weeks postvaccination.
  
  
  RESULTS
  The five SOT recipients (one liver, two kidney and two lung transplants) had a median age of 50 years (range 36 to 53 years), and three were male, who were a median time of three years (range two months to 15 years) post-transplant. All patients were on a double or triple immunosuppressive regimen. The prevaccination pH1N1 titre was 1:10 in four patients and 1:40 in one patient. Seroprotection was observed only in one patient, with a rise in titre from 1:40 at baseline to 1:320 at both two and four weeks after vaccination. This lung transplant recipient had documented previous infection with pH1N1.
  
  
  CONCLUSIONS
  Results of the present small study call into question whether one dose of adjuvanted pH1N1 vaccine can provide seroprotection in SOT recipients.
authors.affiliation: Division of Infectious Diseases, University of Toronto, University Health Network, Toronto, Ontario; ; Postdoctoral Scholarship National Council for Scientific and Technological Development (CNPq), University of Campinas, Sao Paulo, Brazil;
authors.forename: Mariangela R
authors.initials: MR
authors.lastname: Resende
authors.affiliation: Division of Infectious Diseases, University of Toronto, University Health Network, Toronto, Ontario;
authors.forename: Shahid
authors.initials: S
authors.lastname: Husain
authors.affiliation: Public Health Laboratory - Toronto, Ontario Agency for Health Protection and Promotion;
authors.forename: Jonathan
authors.initials: J
authors.lastname: Gubbay
authors.affiliation: Multi-Organ Transplant Program, University of Toronto, University Health Network, Toronto, Ontario.
authors.forename: Lianne
authors.initials: L
authors.lastname: Singer
authors.affiliation: Multi-Organ Transplant Program, University of Toronto, University Health Network, Toronto, Ontario.
authors.forename: Edward
authors.initials: E
authors.lastname: Cole
authors.affiliation: Multi-Organ Transplant Program, University of Toronto, University Health Network, Toronto, Ontario.
authors.forename: Eberhard L
authors.initials: EL
authors.lastname: Renner
authors.affiliation: Division of Infectious Diseases, University of Toronto, University Health Network, Toronto, Ontario;
authors.forename: Coleman
authors.initials: C
authors.lastname: Rotstein
keywords: H1N1; Immunogenicity; Influenza; Solid organ; Transplant; Vaccine