Vaccination against tick-borne encephalitis under therapeutic immunosuppression. Reduced efficacy in heart transplant recipients

Patients after organ transplantation are at an increased risk of microbial infections and might benefit from active vaccination. Due to therapeutic im munosuppression the efficacy of immunizations is, however, reduced and diff icult to predict. Efficacy of vaccination against tick-borne encephalitis ( TBE) using an abbreviated immunization schedule was compared in 31 heart tr ansplant recipients (age: 54.5 +/- 11.5 years, mean time after transplantat ion: 53.5 +/- 23.7 months) under cyclosporine-based immunosuppression and 2 9 controls. TEE vaccination was well tolerated by the transplant recipients ; spectrum and frequency of adverse events were similar to controls. In the transplant patients, seroconversion rate (35% versus 100%; p < 0.001) and the geometric mean of post-vaccinal antibody titres (0.98 (SF: 2.3) U/ml ve rsus 5.46 (2.2) U/ml; p < 0.001) were markedly reduced in comparison to the control group. No clinical or demographic predictors of vaccination succes s could be established in the transplant patients. Due to the limited effic acy, TEE vaccination cannot be recommended as a routine procedure in heart transplant recipients at risk of TEE virus infection. TBE vaccination may b e performed safely in selected cases, but repeated titre controls to confir m vaccination success would be required. (C) 1999 Elsevier Science Ltd. All rights reserved.