Boosting the VZV-Specific Memory B and T Cell Response to Prevent Herpes Zoster After Kidney Transplantation.

Background: Solid organ transplant recipients are at high risk to develop (complicated) herpes zoster (HZ). Booster vaccination could prevent HZ. However, end-stage renal disease (ESRD) patients show poor immunological responses to vaccinations. We studied the effect of a live attenuated VZV booster vaccine on VZV-specific B and T cell memory responses in ESRD patients and healthy controls. NL28557.000.09, www.toetsingonline.nl. Methods: VZV-seropositive patients, aged ≥50 years, awaiting kidney transplantation, were vaccinated with Zostavax®. Gender and age-matched VZV-seropositive potential living kidney donors were included as controls. VZV-specific IgG titers were measured before, at 1, 3 and 12 months post-vaccination. VZV-specific B and T cell responses before, at 3 months and 1 year after vaccination were analysed by flow-cytometry and Elispot, respectively. Occurrence of HZ was assessed at 5 years post-vaccination. Results: 26 patients and 27 donors were included. Median VZV-specific IgG titers were significantly higher at all time-points post-vaccination in patients (mo 1: 3104 IU/ml [1967-3825], p<0.0001; mo 3: 2659 [1615-3156], p=0.0002; mo 12: 1988 [1104-2989], p=0.01 vs. pre: 1397 [613-2248]) and in donors (mo 1: 2981 [2126-3827], p<0.0001; mo 3: 2442 [2014-3311], p<0.0001; mo 12: 1788 [1368-2460], p=0.0005 vs. pre: 1034 [901-1744]. The patients' IgG titers were comparable to the donors' at all time-points. The ratio VZV-specific B cells of total IgG producing memory B cells had increased 3 months post-vaccination in patients (0.85 [0.65-1.34] vs. pre: 0.56 [0.35-0.81], p=0.003) and donors (0.85 [0.63-1.06] vs. pre: 0.53 [0.36-0.79], p<0.0001) and remained stable thereafter in donors. One year post-vaccination, the percentage of CD4+ central memory cells had increased in both patients (0.29 [0.08-0.38] vs. 0.12 [0.05-0.29], p=0.005) and donors (0.12 [0.03-0.37] vs. 0.09 [0.01-0.20], p=0.002) and CD4+ effector memory cells had increased in donors (0.07 [0.02-0.14] vs. 0.04 [0.01-0.12], p=0.007). Only 1 patient experienced HZ, which was non-complicated. Conclusion: VZV booster vaccination increases VZV-specific IgG titers and percentage VZV-specific memory T-cells for at least 1 year both in ESRD patients and healthy controls. VZV-specific memory B cells significantly increased in patients up to 3 months after vaccination. Prophylactic VZV booster vaccination prior to transplantation could reduce HZ incidence and severity after transplantation.

Humoral and cellular response after varicella vaccination in VZV IgG seronegative kidney transplant candidates.

BACKGROUND: In immunocompromised patients, primary infection with VZV may have a disastrous clinical course. Vaccination of VZV-seronegative patients on the waiting list for renal transplantation may prevent severe disease. However, the immunologic response of end-stage renal disease patients to peptide vaccines is far from optimal. Our question was whether end-stage renal disease patients with undetectable VZV-IgG levels were able to mount an adequate humoral and cellular response to a live attenuated varicella vaccine. METHODS: Kidney transplant candidates with undetectable VZV levels were vaccinated twice with a live attenuated varicella vaccine at an interval of 6weeks. VZV IgG levels were analysed till 2years after vaccination. The VZV-specific T-cell reactivity was determined prior to vaccination and after transplantation. RESULTS: Seventy-seven percent (40/52) of the vaccinees reached positive VZV-IgG levels after vaccination (responders). Eighty-two percent (9/11) showed an increase in VZV-specific CD4+ memory T-cells (both central and effector memory cells). The percentage VZV-specific CD8+ memory T-cells did not increase. None of the non-responders suffered from primary VZV after transplantation. No severe vaccine-related adverse events were reported, only spontaneously resolving local skin irritation. CONCLUSION: The live attenuated varicella vaccine evokes positive VZV IgG-levels and VZV-specific memory T-cells in VZV-seronegative potential kidney transplant candidates.