Immune response to an adjuvanted influenza A H1N1 vaccine (Pandemrix®) in renal transplant recipients

Background. In the course of the influenza A H1N1 pandemic, transplanted patients were recommended to receive vaccination. In the present study, we evaluated the immune response to an adjuvanted influenza A H1N1 vaccine (Pandemrix (R)) in renal allograft recipients. Methods. Sixty patients and 22 healthy controls participated in a prospective observational study and received a single dose of Pandemrix (R). H1N1 antibody titres as well as anti-HLA antibodies were determined before and after vaccination. In 19 patients, a booster vaccination was performed and the outcome of all vaccinated renal allograft recipients (n = 107) in our clinic was reviewed. Results. Two out of sixty patients had an elevated influenza A H1N1 titre before vaccination. Of the remaining 58 patients, only 20/58 (34.5%) developed a protective immune response in contrast to 20/22 (91%) of the control group. After booster vaccination, a protective titre was present in 8/19 (42%) of patients. Of the 107 patients, 6 (5.6%) developed new donor-specific HLA antibodies after vaccination. Conclusions. These data suggest that Pandemrix (R) does not provide a protective immune response in the majority of kidney transplant recipients. Therefore, for new vaccines, efficacy as well as safety profiles should be evaluated in this subgroup of patients.