Negative IgG Varicella Zoster Virus Antibody Status: Immune Responses Pre and Post Re-immunization

INTRODUCTION Varicella zoster virus (VZV) causes chicken pox and herpes zoster and is a self-limiting disease in healthy children. Vaccination is recommended for children, adolescents, and adults. This study discusses a healthy pediatric patient with negative immunoglobulin (Ig) G VZV antibody (Ab) status after two doses of varicella vaccine and then subsequently re-immunized. Since measurement of serum IgG titers alone may not reflect vaccine protection, we further evaluated cell-mediated and humoral immune responses before and after re-immunization. METHODS Blood lymphocyte distributions (CD3+CD4+, CD3+CD8+, CD19+, CD4+CD60+, CD8+CD60+), total serum IgG and IgE levels, and VZV-IgG, IgM, and IgE Ab levels were measured in a healthy girl (14 year-old) pre- and post-VZV re-immunization (weeks 1-8) [flow microfluorimetry, nephelometry, ELISA, enzyme immunoassay (EIA)]. RESULTS Pre-re-immunization numbers of T cells (CD3+CD4+, CD3+CD8+, CD4+CD60+, CD8+CD60+) and B cells (CD19+) were within normal ranges. After re-immunization, numbers of T cells remained relatively unchanged; however, numbers of CD19+ B cells increased (48%). Total serum IgG was low (757 mg/dl), and total serum IgE was normal (30 IU/ml). Pre-reimmunization, VZV IgG and IgM Ab levels were negative (< 0.90 and < 0.90 antibody index, respectively), and VZV IgE levels were undetectable. After re-immunization, VZV IgG Ab levels were positive (690.70 Ab index), VZV IgM Ab levels were negative (≤ 0.90), and VZV IgE levels remained undetectable. CONCLUSION Vaccination with the VZV vaccine may boost IgG but not IgE-specific viral responses and concurrently increase the numbers of CD19+ B cells.