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

OBJECTIVES

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 cell-mediated immune (CMI) responses 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.