Safety and Immunogenicity of Zoster Vaccine Live in Human Immunodeficiency Virus-Infected Adults With CD4+ Cell Counts >200 Cells/mL Virologically Suppressed on Antiretroviral Therapy.

BACKGROUND

Herpes zoster (HZ) risk is increased in human immunodeficiency virus (HIV)-infected persons. Live attenuated zoster vaccine (ZV) reduces HZ incidence and severity in adults; safety and immunogenicity data in HIV-infected adults are limited.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial in HIV-infected adults virally suppressed on antiretroviral therapy (ART). Participants, stratified by CD4+ count (200-349 or ≥350 cells/µL), were randomized 3:1 to receive ZV or placebo on day 0 and week 6. The primary endpoint was serious adverse event or grade 3/4 signs/symptoms within 6 weeks after each dose. Immunogenicity (varicella zoster virus [VZV]-specific glycoprotein enzyme-linked immunosorbent assay and interferon-γ enzyme-linked immunospot assay responses) was assessed at 6 and 12 weeks postvaccination.

RESULTS

Of 395 participants (296 ZV vs 99 placebo), 84% were male, 47% white, 29% black, and 22% Hispanic; median age was 49 years. Safety endpoints occurred in 15 ZV and 2 placebo recipients (5.1% [95% confidence interval {CI}, 2.9%-8.2%] vs 2.1% [95% CI, .3%-7.3%]; P = .26). Injection site reactions occurred in 42% of ZV (95% CI, 36.3%-47.9%) vs 12.4% of placebo recipients (95% CI, 6.6%-20.6%) (P < .001). Week 12 median natural log VZV antibody titer was higher for ZV (6.30 [Q1, Q3, 5.64, 6.96]) vs placebo (5.48 [Q1, Q3, 4.63, 6.44]; P < .001) overall and in the high CD4+ stratum (P = .003). VZV antibody titers were similar after 1 or 2 ZV doses. Polymerase chain reaction-confirmed HZ occurred in 2 participants (1 ZV; 1 placebo); none was vaccine strain related.

CONCLUSIONS

Two doses of ZV in HIV-infected adults suppressed on ART with CD4+ counts ≥200 cells/µL were safe and immunogenic.

CLINICAL TRIALS REGISTRATION: NCT00851786.