Antibody response to VZV vaccination in HIV infected children

Abstract

AimTo evaluate the effectiveness of varicella vaccination based on the presence of VZV antibodies in HIV-infected children and to establish factors influencing vaccination response. BackgroundVZV vaccination is recommended in HIV-infected children without severe immunodeficiency. This group of children may not produce sufficient immunologic response. Materials and methodsPost vaccination antibodies were evaluated in 21 HIV-infected children who received 2 doses of varicella vaccine. VZV antibodies were checked after the second vaccine dose using VIDAS Varicella-Zoster IgG ELFA technique. All patients have been receiving combined antiretroviral treatment (cART). The analyzed factors included: age at HIV diagnosis, age when receiving the first vaccine dose, Centers for Disease Control and Prevention (CDC) classification at diagnosis, at time of vaccination and at evaluation. ResultsPost-vaccination VZV antibodies were present in 52% of patients. HIV infection was diagnosed at the mean age of 13 months (range 1 month to 4.5 years). Prior to evaluation 11/21 children had experienced moderate to severe HIV symptoms. Six children experienced severe immunodeficiency, 6 were moderate immunodeficient in the past, 46% of them responded to vaccination. At time of vaccination all the children were immunocompetent. At the time of the antibodies evaluation 20 children were classified N1/A1, one received C1 classification due to HIV encephalopathy. The subjects who had VZV protective antibody titers had shorter time since vaccination and were less likely to have prior immunodeficiency. No children developed varicella during the mean 3.5 years of follow-up. ConclusionSerological immune response to varicella vaccination in HIV-infected children was insufficient.