A review of the varicella vaccine in immunocompromised individuals

BACKGROUND: Individuals with underlying cell-mediated immunodeficiency disorders are at high risk of developing severe, life-threatening illness associated with varicella-zoster virus infection. A live-attenuated varicella vaccine is recommended for routine childhood immunisation in some countries. In healthy children, the vaccine is efficacious and safe but because immunocompromised individuals may be unable to limit replication of live-attenuated vaccine viruses, the varicella vaccine is not recommended for them and there are few exceptions. OBJECTIVES: The purpose of this paper is to review the published studies addressing the use of the varicella vaccine in people with cell-mediated immunodeficiency disorders. METHODS: A computerised search on the PubMed database was used to collect the relevant papers published up to March 2003. RESULTS: The varicella vaccine has been extensively studied in susceptible children with acute lymphoblastic leukaemia in remission, but studies involving individuals with other immunodeficiency disorders are scarce. Some of the current recommendations are based on very few and small studies with short follow-up. Immunocompromised individuals should be given the varicella vaccine only with complete knowledge of their clinical and immunological conditions and after considering the risks of natural infection and vaccination.