Varicella vaccine has been demonstrated to be safe and immunogenic in children with HIV infection with minimal symptoms and CD4 cell percentages according to their age of 25% or more.[16] A study evaluated the safety and efficacy of varicella vaccine in children with either moderate symptoms and CD4 cell percentages more than 15%, or a history of severe immunosuppression who had achieved immune reconstitution. Regardless of immunological category, 79% of vaccine recipients with HIV infection developed VZV-specific antibody or cell-mediated immunity, or both, 60 days after the immunisation series.[17] The current recommendations from the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention states that single-antigen varicella vaccine should be administered to children with HIV infection with a CD4 T lymphocyte percentage greater than 15%, whereas the Australian guidelines currently recommend vaccination at greater than 25%.[18],[19],[20] The ACIP also recommend that single-antigen varicella vaccine may be considered in VZV-seronegative adolescents or adults with HIV infection with a CD4 cell count greater than 200 cells/μL. Two doses should be administered 3 months apart.[21],[22] A recent review reported the use of live-attenuated HZ vaccine in adults with HIV infection with a CD4 cell count over 200 cells/µL with immunogenic response, a good safety profile and no cases of vaccine strain infection.[23]
Zoster immunoglobulin is indicated for patients with HIV infection within 96 hours of significant first VZV exposure (e.g. household or classroom contact), and protection may last for approximately 3 weeks or alternatively a thymidine kinase inhibitor (acyclovir) can be given up to 7 days post exposure.[24]
In terms of prevention of HZ recurrences, one study found that the use of oral acyclovir among patients with HIV infection at a dose of 400 mg twice daily decreases the risk of HZ recurrence by 62%, although this result has not been repeated.[25]