title: Effect of two injections of non-adjuvanted influenza A H1N1pdm2009 vaccine in renal transplant recipients: INSERM C09-32 TRANSFLUVAC trial.
abstract: BACKGROUND
  Enhancing vaccine immunogenicity in kidney transplant recipients, particularly against influenza, is required since the immunosuppression used to prevent graft rejection limits vaccine immunogenicity. We therefore investigated the immunogenicity and safety of a double dose non-adjuvanted vaccination regimen against influenza H1N1pdm2009 in kidney transplant adult recipients.
  
  
  METHODS
  A prospective single-arm study was conducted including 121 renal transplant recipients under triple immunosuppressive regimen. Patients received 2 injections (day 0, day 21) of an inactivated, non-adjuvanted H1N1pdm2009 vaccine. Immunogenicity (hemagglutination-inhibition [HI] antibodies and anti-hemagglutin [HA] specific T cells) was evaluated after one and two injections (day 21, day 42) and at 6 months (day 182).
  
  
  RESULTS
  The seroprotection rate (HI antibody titer≥1/40) was 19% at day 0 (n=119), 53% at day 21 (n=118), 60% at day 42 (n=116) (p=0.013; day 42 vs. day 21) and 56% at day 182 (n=113). The seroconversion rate was 24% and 32%, the geometric mean fold rise was 3.7 and 4.6 after the first and second injections, respectively. T-cell immunity to the H1N1pdm2009 vaccine showed a two-fold increase from baseline, though not statistically significant, in H1N1pdm2009-HA-specific CD4+ and CD8+ T cells in 34% and 48% of cases, respectively. No rejection episodes related to vaccination were observed while the donor-specific antibodies and creatinine clearance remained unchanged throughout the study.
  
  
  CONCLUSIONS
  Administration of two doses of the non-adjuvanted influenza H1N1pdm2009 vaccine in renal transplant patients is safe and induces a significant seroprotection, not strong enough yet to meet European or US requirements for adults below 60 years, but comparable to seroprotection levels usually observed in the non immunosuppressed elderly population or conferred by a single dose of adjuvanted vaccine in solid organ transplant recipients. These results provide useful indications for future strategies required to improve immunogenicity of vaccines against influenza in transplanted patients.
authors.affiliation: INSERM UMRS-945, Laboratoire Immunité et Infection, Groupe Hospitalier Pitié-Salpêtrière Paris, France.
authors.forename: Nicole
authors.initials: N
authors.lastname: Le Corre
authors.forename: Fréderic
authors.initials: F
authors.lastname: Thibault
authors.forename: Claire
authors.initials: C
authors.lastname: Pouteil Noble
authors.forename: Vincent
authors.initials: V
authors.lastname: Meiffrédy
authors.forename: Sameh
authors.initials: S
authors.lastname: Daoud
authors.forename: Remi
authors.initials: R
authors.lastname: Cahen
authors.forename: Isabelle
authors.initials: I
authors.lastname: Charreau
authors.forename: David
authors.initials: D
authors.lastname: Bottigioli
authors.forename: Cécile
authors.initials: C
authors.lastname: Dollinger
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Aboulker
authors.forename: Brigitte
authors.initials: B
authors.lastname: Autran
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Morelon
authors.forename: Benoit
authors.initials: B
authors.lastname: Barrou
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D007251:Influenza, Human / Q000517:prevention & control* / Q000821:virology; D007273:Injections, Intramuscular; D016030:Kidney Transplantation / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013601:T-Lymphocytes / Q000276:immunology; D014180:Transplantation; D014611:Vaccination / Q000009:adverse effects / Q000379:methods; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007252:Influenza Vaccines