Long-term immunogenicity and safety of RZV primary vaccination and revaccination in kidney transplant recipients

AbstractObjectives Immunogenicity and safety of recombinant zoster vaccine (RZV) were evaluated in the long-term and after revaccination in kidney transplant (KT) recipients on daily chronic immunosuppressive treatment. Methods This phase 3b, single-arm, multicenter trial, evaluated KT recipients for varicella zoster virus (VZV) glycoprotein E (gE)-specific humoral and cellular immune responses (CMI) and safety ~4–8 years post-primary RZV series (two doses) given at ≥18 years of age; and after revaccination (two doses, one month apart), ~6–8 years post-primary RZV series. Solicited and unsolicited adverse events (AEs) were recorded for seven and 30 days after each revaccination dose. Serious AEs (SAEs), including biopsy-proven allograft rejection and potential immune-mediated diseases, were recorded throughout the study. Results 68 participants were enrolled and 47 revaccinated. Persistent humoral and CMI responses remained ≥2.4-fold and ≥6.1-fold above pre-vaccination levels. One revaccination dose provided robust humoral (22.3-fold) and CMI (276.2-fold) above pre-vaccination responses. No vaccine-related SAEs were observed. Conclusions This study demonstrates sustained immunogenicity against VZV gE for up to ≥8 years, functional immune memory with a robust anamnestic response at 6–8 years, and an acceptable safety profile after revaccination, reinforcing RZV's value for herpes zoster prevention in adult KT recipients on daily immunosuppression. Clinical Trial Registration NCT04176939