Immune response to Haemophilus influenzae type b vaccination in renal transplant recipients with well-functioning allografts

Background: Haemophilus influenzae infection is a mild and self-limited dis ease in the healthy population. However, it may show an aggressive course i n the immunocompromised state which underlines the importance of vaccinatio n against this agent. On the other hand, posttranplant immunosuppression ma y impair immune responses and thus the efficacy of the vaccination. Methods : Forty-three renal transplant recipients with well-functioning allografts were immunized with H. influenzae type b vaccine in order to investigate th e immune response. The patients received a double or a triple immunosuppres sive protocol. Seven healthy members of the dialysis unit served as control s. After obtaining basal serum samples, the patients and the control subjec ts were immunized with H. influenzae type b conjugate vaccine. After 6 and 12 weeks, serum samples obtained again to determine H. influenzae type b an tibody titers. Results: The antibody titers 6 and 12 weeks after vaccinatio n were significantly higher as compared with the basal values, similar to t hose of the control subjects, These titers did not show statistically signi ficant differences between the double and triple immunosuppressive therapy groups. After 12 weeks of vaccination, the antibody titers did not show a s tatistically significant difference as compared with those obtained after 6 weeks. Conclusion: H. influenzae type b vaccination is safe and effective in patients with well-functioning renal allografts and should be recommende d to renal transplant recipients who may have the risk of invasive disease on the basis of the immunosuppressive state.