Abstract
BACKGROUND: Protection against herpes zoster is primarily conferred by cell-mediated immunity. However, anti-varicella-zoster virus (VZV) glycoprotein (anti-gp) antibody responses to zoster vaccine live (ZVL) are correlated with protection, suggesting a potential protective role for antibody. Detailed studies of antibody responses to the recombinant zoster vaccine (RZV) are provided. METHODS: We compared enzyme-linked immunosorbent assay-measured anti-VZV glycoproteins (anti-gp) and glycoprotein E (anti-gE) antibody levels and avidity in 159 participants randomized to RZV (n = 80) or ZVL (n = 79) recipients over 5 years after vaccination and identified predictors of antibody persistence. RESULTS: The comparison between vaccine groups showed higher anti-gE and anti-gp antibody levels after RZV than after ZVL over the 5-year study duration. RZV recipients also had higher anti-gE avidity for 5 years and higher anti-gp avidity in the first year after vaccination. Compared with prevaccination levels, RZV recipients maintained higher levels of anti-gE antibodies and avidity for 5 years, whereas ZVL recipients only maintained higher anti-gE avidity. Anti-gp antibody levels and avidity decreased to prevaccination levels or below beyond 1 year after vaccination in both groups. Independent predictors of persistence of antibody levels and avidity included vaccine type, prevaccination and peak antibody levels and avidity, prevaccination and peak cell-mediated immunity, and age. Sex or prior ZVL administration did not affect persistence. CONCLUSIONS: Antibody responses and avidity were higher and more persistent in RZV than in ZVL recipients. The effect of age on antibody persistence in RZV recipients is novel.