title: Varicella-zoster immunization in pediatric liver transplant recipients: safe and immunogenic.
abstract: Varicella can have a severe course in immunosuppressed patients. Although prevention is fundamental, live-attenuated varicella-zoster (VZV) vaccine is not currently recommended in transplant recipients. Our aims were to (1) evaluate VZV immunity in pediatric liver transplant (LT) recipients; (2) immunize (two doses) seronegative patients post-LT; (3) monitor vaccine safety, (4) assess B and T cell vaccine responses. All patients followed at the Swiss National Pediatric LT Center were approached and 77/79 (97.5%) were enrolled (median age 7.8 years). Vaccine safety was monitored by standardized diary cards and phone calls. VZV-specific serology and CD4(+)  T cells were assessed before and after immunization. Thirty-nine patients (51.1%) were seronegative including 14 children immunized pre-LT. Thirty-six of 39 seronegative patients were immunized post-LT (median 3.0 years post LT). Local (54.8%) and systemic (64.5%) reactions were mild and transient. The frequency of VZV-specific CD4(+)  T cells and antibody titers increased significantly (respectively from 0.085% to 0.16%, p = 0.04 and 21.0 to 1134.5 IU/L, p < 0.001). All children reached seroprotective titers and 31/32 (97%) patients assessed remained seroprotected at follow-up (median 1.7 years). No breakthrough disease was reported during follow-up (median 4.1 years). Thereby, VZV vaccine appears to be safe, immunogenic and provide protection against disease in pediatric LT patients.
authors.affiliation: Department of Pediatrics, Division of General Pediatrics, Children's Hospital of Geneva, University Hospitals of Geneva, Switzerland. Klara.PosfayBarbe@hcuge.ch
authors.forename: K M
authors.initials: KM
authors.lastname: Posfay-Barbe
authors.forename: L F
authors.initials: LF
authors.lastname: Pittet
authors.forename: C
authors.initials: C
authors.lastname: Sottas
authors.forename: S
authors.initials: S
authors.lastname: Grillet
authors.forename: B E
authors.initials: BE
authors.lastname: Wildhaber
authors.forename: M
authors.initials: M
authors.lastname: Rodriguez
authors.forename: L
authors.initials: L
authors.lastname: Kaiser
authors.forename: D C
authors.initials: DC
authors.lastname: Belli
authors.forename: V A
authors.initials: VA
authors.lastname: McLin
authors.forename: C A
authors.initials: CA
authors.lastname: Siegrist
mesh_terms: D000914:Antibodies, Viral / Q000276:immunology*; D002644:Chickenpox / Q000276:immunology / Q000517:prevention & control*; D019433:Chickenpox Vaccine / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000517:prevention & control; D006085:Graft Survival; D006562:Herpes Zoster / Q000276:immunology / Q000517:prevention & control*; D053061:Herpes Zoster Vaccine / Q000008:administration & dosage; D006801:Humans; D007114:Immunization / Q000379:methods; D016867:Immunocompromised Host / Q000276:immunology*; D007223:Infant; D016031:Liver Transplantation / Q000009:adverse effects / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D018570:Risk Assessment; D017751:Safety Management; D014181:Transplantation Immunology; D016896:Treatment Outcome
chemical_list: D000914:Antibodies, Viral; D019433:Chickenpox Vaccine; D053061:Herpes Zoster Vaccine