title: Pandemic influenza A H1N1 vaccine in recipients of solid organ transplants: immunogenicity and tolerability outcomes after vero cell derived, non-adjuvanted, whole-virion vaccination.
abstract: During the 2009/10 pandemic of influenza A (H1N1), the American Society of Transplantation and other health organizations recommended that immunocompromised patients should be vaccinated as the key preventive measure. Since there are no data available for the immunogenicity of the unadjuvanted pandemic influenza vaccine in immunocompromised patients - as opposed to the adjuvanted preparation - the objective of this study was to evaluate the immunogenicity of an adjuvant-free H1N1 vaccine in recipients of solid organ transplants. Patients were recruited at the Vienna General Hospital, Austria. The vaccination schedule consisted of 2 doses of a whole-virion, vero cell derived, inactivated, non-adjuvanted influenza A/California/07/2009 (H1N1) vaccine given with an interval of 3 weeks. A hemagglutination inhibition (HI) assay on blood samples obtained prior to the first and after each vaccination was used for serologic analysis. The primary immunologic endpoint was the seroconversion rate, defined as the proportion of subjects with an individual 4-fold increase in HI titer of at least 1:40. In addition, virus-specific IgG antibodies to the pandemic H1N1 strain were measured using a commercially available ELISA. Twenty-five organ transplant patients (16 males, 9 females) aged 25-79 years were vaccinated and provided blood samples for serologic analysis. The time elapsed since transplantation was 10 months to 25 years (mean: 9 years; 95% CI 6-13 years). The vaccine was well tolerated and no local adverse events were noticed. After two vaccinations 37% of the patients demonstrated seroconversion in the HI assay as defined above and 70% had virus-specific IgG antibodies. Among the HI vaccine responders were 6 of 14 heart transplant recipients and 1 of 4 liver transplant recipients. The number and type of immunosuppressive agents did not significantly differ in their effect on the immune response. Our results show that the novel vero cell derived and adjuvant-free pandemic A/California/07/2009 (H1N1) influenza vaccine induced limited but measurable immune responses in adult recipients of solid organ transplants.
authors.affiliation: Division of Infectious Diseases and Tropical Medicine, Department of Medicine 1, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria.
authors.forename: Heimo
authors.initials: H
authors.lastname: Lagler
authors.forename: Judith M
authors.initials: JM
authors.lastname: Wenisch
authors.forename: Selma
authors.initials: S
authors.lastname: Tobudic
authors.forename: Guido A
authors.initials: GA
authors.lastname: Gualdoni
authors.forename: Susanne
authors.initials: S
authors.lastname: Rödler
authors.forename: Susanne
authors.initials: S
authors.lastname: Rasoul-Rockenschaub
authors.forename: Peter
authors.initials: P
authors.lastname: Jaksch
authors.forename: Monika
authors.initials: M
authors.lastname: Redlberger-Fritz
authors.forename: Theresia
authors.initials: T
authors.lastname: Popow-Kraupp
authors.forename: Heinz
authors.initials: H
authors.lastname: Burgmann
mesh_terms: D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D001317:Austria; D002522:Chlorocebus aethiops; D005260:Female; D006385:Hemagglutination Inhibition Tests / Q000379:methods; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology* / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D012698:Serologic Tests / Q000379:methods; D014181:Transplantation Immunology / Q000276:immunology*; D014611:Vaccination / Q000379:methods; D014709:Vero Cells; D014771:Virion / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007252:Influenza Vaccines