Live Attenuated Zoster Vaccine Boosts Varicella Zoster Virus (VZV)–Specific Humoral Responses Systemically and at the Cervicovaginal Mucosa of Kenyan VZV-Seropositive Women

BACKGROUND: Attenuated varicella zoster virus (VZV) is a promising vector for recombinant vaccines. Because human immunodeficiencyvirus (HIV) vaccines are believed to require mucosal immunogenicity, we characterized mucosal VZV-specific humoral immunity following VZV(Oka) vaccination. METHODS: Adult Kenyan VZV-seropositive women (n = 44) received a single dose of the live zoster VZV(Oka) vaccine. The anamnestic responses to the virus were followed longitudinally in both plasma and mucosal secretions using an in-house glycoprotein enzyme-linked immunosorbent assay and safety and reactogenicity monitored. VZV seroprevalence and baseline responses to the virus were also characterized in our cohorts (n = 288). RESULTS: Besides boosting anti-VZV antibody responses systemically, vaccination also boosted anti-VZV immunity in the cervicovaginal mucosa with a 2.9-fold rise in immunoglobulin G (P < .0001) and 1.6-fold rise in immunoglobulin A (IgA) (P = .004) from the time before immunization and 4 weeks postvaccination. Baseline analysis demonstrated high avidity antibodies at the gastrointestinal and genital mucosa of VZV-seropositive women. Measurement of VZV-specific IgA in saliva is a sensitive tool for detecting prior VZV infection. CONCLUSIONS: VZV(Oka) vaccine was safe and immunogenic in VZV-seropositive adult Kenyan women. We provided compelling evidence of VZV ability to induce genital mucosa immunity. CLINICAL TRIALS REGISTRATION: NCT02514018.