Immunity Against Varicella in Pediatric Orthotopic Liver Transplantation Recipients

Study Overview
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Brief Summary
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Varicella is a vaccine-preventable disease, which can be severe in immunosuppressed children. Currently, the (live) vaccine is not recommended in pediatric orthotopic liver transplant recipients. Furthermore, protection due to naturally acquired immunity to VZV or post-immunization isn't well described in this population.The questions asked are: What is the influence of the immunosuppression required after orthotopic liver transplantation (OLT) on the maintenance of VZV-specific immunity elicited by wild-type varicella infection before OLT transplantation? What is the influence of the immunosuppression required after OLT on VZV-specific immunity elicited by varicella immunization before OLT transplantation? What is the influence of the residual immunosuppression at ≥ 12 months after OLT transplantation on the induction of VZV-specific B and T cell responses elicited by VZV vaccination after OLT transplantation? What is the influence of the residual immunosuppression at ≥ 12 months after OLT transplantation on the persistence / waning of B and T cell responses elicited by VZV vaccination?

Detailed Description
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VZV vaccine given to pediatric liver transplant recipients at least one year after transplantation if tehy fulfill inclusion criteria and give informed consent.

Official Title
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Induction and Maintenance of Immunity Against Varicella in Pediatric Orthotopic Liver Transplantation Recipients: a Retrospective and Prospective Nationwide Study in Switzerland

Conditions
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Liver Disease, Immunosuppression, Varicella

Intervention / Treatment
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* Biological: Vaccination with VZV vaccine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Children either awaiting or recipients of a liver transplantation followed at the Children's Hospital of Geneva, Switzerland If vaccination offered: > 12 months of age Exclusion Criteria: Known wild type varicella exposure within four weeks of the initial vaccine Immunoglobulins administered within the 5 months preceding the receipt of varicella vaccine. Antiviral agents administered during the preceding 4 weeks Febrile illness (>38.5°) in the 72 hours before vaccine administration Chronic aspirin therapy Any other live vaccinations within four weeks of receipt of varicella vaccine Female patients in childbearing age will have a pregnancy test at enrollment, and at the time of the second vaccine.

Ages Eligible for Study
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Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Varicella vaccine<br>2-3 doses of Varicella vaccine to seronegative patients two months apart | Biological: Vaccination with VZV vaccine<br>* Varicella vaccination 2 doses 2 months apart.<br>* Other names: Varilrix;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Safety of VZV vaccine in OLTx recipients | Antibody response measured after vacination with long-term f/u | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Efficacy of VZV vaccine in immunosuppressed OLTx recipients | Protection from disease monitored | 3 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Orthotopic liver transplantation, Pediatric, Immunosuppression, Varicella vaccine, B cell response, T cell response, Antibodies, Varicella, Chickenpox, transplantation