Serological response to influenza A H1N1 vaccine (Pandemrix®) and seasonal influenza vaccine 2009/2010 in renal transplant recipients and in hemodialysis patients.

In the present study, antibody response to seasonal influenza vaccination and to the adjuvanted one-shot influenza A H1N1 vaccine (Pandemrix(®)) was investigated in 57 hemodialysis (HD) patients and 48 renal transplant (RT) recipients. Specific antibodies were measured by hemagglutination inhibition (HI) test using a pandemic H1N1 strain and a seasonal H3N2 virus. HI titers of ≥1:40 were considered as protective. Hemodialysis patients showed seroprotection against pandemic H1N1 in 35.1%, against seasonal influenza in 36.8% and against both in 14.0%. In comparison, renal transplant recipients developed protective antibody titers against the pandemic H1N1 virus in 47.9%, against the seasonal H3N2 strain in 31.3% and against both in 18.8%. HD patients and renal transplant recipients younger than 60 years developed protective antibody response to the pandemic influenza H1N1 vaccine in 50.0% of the HD patients and 55.2% of the RT recipients and against seasonal influenza in 45.0/20.7% (HD/RT) of the cases. Patients aged ≥60 years showed seroprotection against pandemic influenza in 27.0/36.8% (HD/RT) and against seasonal influenza in 32.4/47.4% (HD/RT). Side effects were reported in only four patients. In hemodialysis patients and renal transplant recipients, vaccination against pandemic H1N1 and seasonal influenza is well tolerated. However, more than a half of these patients did not develop seroprotective antibody levels. Thus, new vaccines and altered vaccination regimes are likely necessary to achieve relevant antibody levels in these patient groups.