Response and Clearance of Viral DNA Following Administration of Live Attenuated Varicella Vaccine.

Varicella zoster virus (VZV) can lead to significant morbidity and mortality in transplant recipients. Current recommendations suggest a 4 week waiting period between vaccination and transplantation and consideration of booster immunizations if antibody response does not reach target levels. This four week waiting period can result in delayed transplant, rejection of an optimal organ, or missed opportunity to vaccinate. However, these recommendations are not evidence based. This is a prospective study to look at the immune response to varicella vaccine in children with chronic liver disease. Investigators will evaluate: 1. the time at which VZV DNA becomes undetectable in blood and saliva by PCR after vaccination in children with chronic liver disease and 2. the difference in humoral and cell mediated immune response to varicella immunization between children with chronic liver disease and healthy children.