Clinical Trial Evaluating Efficacy and Safety of One Dose Versus Two Doses of Influenza Vaccination (TraNsgripe)

• Seroconversion rates [ Time Frame: At 5, 10, 15 weeks, and 12 months after the first vaccine dose ]
  Difference in seroconversion rates in both treatment groups at 5, 10, 15 weeks, and 12 months after the first vaccine dose (percent of patients with 4 x increase in the pre-vaccination titers).
  
  

• Postvaccination antibody titers [ Time Frame: At 5, 10, 15 weeks, and 12 months after the first vaccine dose. ]
  Geometric average postvaccination antibody titers and rate of increase between pre-and post-vaccination geometric mean, post-vaccination seroprotection rate (or percentage of individuals with a titer 1 / 40 as measured by RIH).
  
  
• Safety. [ Time Frame: At 5, 10, 15 weeks, and 12 months after the first vaccine dose ]
  Occurrence of grade 3 or 4 toxicity, death, hospitalization, retransplantation, acute rejection and chronic rejection
  
  
• Efficacy [ Time Frame: At 5, 10, 15 weeks, and 12 months after the first vaccine dose ]
  Detection of clinical cases of influenza following immunization. Nasal swabs to confirm infection with influenza virus by RT-PCR (Reverse transcription polymerase chain reaction).
  
  
• Antibody anti-HLA [ Time Frame: At 5, 10, 15 weeks, and 12 months after the first vaccine dose ]
  Characterize the flu vaccine effect (one dose and two doses) through the antibody anti-HLA levels, ant its influence on the rejection rate in solid organ transplant recipients, by means of immunologic sub-study.
  
  
• Cellular response [ Time Frame: At 5, 10, 15 weeks, and 12 months after the first vaccine dose ]
  Determination of the T cells specific immune response measured by production of INFg, IL-2 and IL-4 in the cytoplasm of CD4+ and CD8 + (mononuclear cells) specific for influenza virus by direct immunofluorescence and flow cytometry analysis.
  
  
• Clinical complications [ Time Frame: At 5, 10, 15 weeks, and 12 months after the first vaccine dose ]
  Clinical severity (hospitalization, ICU admission, death, rejection). Time to clinical stability will be register.
  
  

The purposes of this study are:

1. Evaluate the efficacy and safety of a double dose of seasonal flu vaccine compared to a single dose.
2. Determine the specific cellular immune response produced after the first and second vaccine doses of seasonal flu vaccine by in vitro stimulation of specific memory cells (A and B flu viruses).
3. Evaluate the humoral immune response produced after one dose vs two doses of seasonal flu vaccine by the measure of serum antibody levels.
4. Evaluate clinical efficacy of stationary flu vaccine in solid organ transplant recipients.
5. Evaluate a long term cellular and humoral response(1 year) of seasonal flu vaccine.
6. Characterize the genetic expression profile of immune response after the flu vaccine in solid organ transplant recipients by means of a genetic sub-study.
7. Characterize the flu vaccine effect (one dose and two doses) through the antibody anti-HLA(human leukocyte antigen), and its influence on the rejection rate in solid organ transplant recipients, by means of immunologic sub-study.