Management, prevention and vaccination

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]