Prevention of Varicella Zoster Virus (VZV)-Reactivation in HIV-positive Individuals Enrolled in a Prospective Immunogenicity and Safety Trial of VZV Vaccine: PROVE-IT-Study

Inclusion criteria: All individuals * Age \>18 years * Male, or female with negative urine pregnancy test * VZV-seropositive (serologically documented) * Agree to use a barrier method of birth control (such as a condom) * Written informed consent HIV positive individuals on ART (group A1-A3) * Continuous ART for \>3 months before baseline * No change of ART regimen within 1 month before baseline * HIV-RNA (value must be \<3 months old )\<50 copies/ml at last visit * CD4-count (value must be \<3 months old) \> 500 cells/µl for group A1, 350-500 cells/µl for group A2 and 250 -349 cells/µl for group A3 * Participation in the SHCS HIV-positive individuals without ART (group B) * HIV-1 RNA \>1000 copies/ml (\<3 months before baseline) * CD4-cell count \>500 cells/µl (\<3 months before baseline) * Participation in the SHCS Healthy HIV-negative volunteers (group C) * Negative HIV-screening test (\<3 months before baseline) * CD4 cell count \>500 cells/µl Exclusion criteria: Common exclusion criteria * Contraindications on ethical grounds * Involvement in a conflicting (vaccine or investigational drug) clinical trial (except from the participation in the Swiss HIV Cohort Study). * Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders or dementia of the subject. * Pregnancy or breast feeding. * Other clinically relevant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc), * Known or suspected non-compliance, drug- or alcohol abuse. Specific exclusion criteria * Fever \> 38.3 °C or acute illness during the last 4 weeks * Exposure to chickenpox or shingles within four weeks prior to study entry * History of shingles * Immunosuppression due to disease (other than HIV) or due to medication within 30 days of study entry (eg corticosteroids) * Household contact with known immunodeficiency (e.g. HIV-positive with CD4 \<250 cells/µl) * Immunoglobulin or blood product treatment within 1 year prior or 2 month after study vaccination * Previous allergic reaction to vaccine components (i.e. neomycin or gelatin) * Vaccination with a life attenuated vaccine one month prior to study entry * History of chickenpox vaccination * Treatment with anti-herpes drugs 4 weeks before baseline * Severe coagulation disorder or oral anticoagulant treatment * Laboratory exclusion criteria. * Thrombocytopenia \< 50x 103/?l * Haemoglobin \<12 g/dl * More than threefold elevation of ALT * Creatinine of more than150 µmol/l * Glucose \>10 mmol/l