Women who received varicella vaccine versus natural infection have different long-term T cell immunity but similar antibody levels

Background: Varicella-zoster virus (VZV) infection during pregnancy is associated with serious fetal anomalies. The live-attenuated VZV vaccine was approved in 1995, so many vaccinated women are now of childbearing age. The question of long-term immunity to varicella is critical because breakthrough chickenpox can occur after vaccination.
Objective: To compare humoral and T cell immunity between women of childbearing age who were immunized by vaccination or chickenpox disease.
Study design: Non-pregnant females between 18 and 36 years old with a history of VZV immunization (n = 20) or prior chickenpox disease (n = 20) were recruited. IgG antibody titers and T cell responses were measured by flow cytometry-based methods in serum and peripheral blood, respectively.
Results: There were no significant differences in median antibody titers between vaccinated and chickenpox groups (p = 0.34). The chickenpox group had significantly higher levels of VZV antigen-specific CD4 T cells (p = 0.004).
Conclusion: Natural infection induced higher VZV-specific T cell immune responses than vaccination.