A systematic literature review of the recombinant subunit herpes zoster vaccine use in immunocompromised 18-49 year old patients

Background: The adjuvanted recombinant zoster vaccine (RZV) is indicated for prevention of herpes zoster (HZ) in adults aged >= 50 years. Questions regarding the use of RZV in immunocompromised patients < 50-year-old, who are at increased risk for HZ, were raised. Objectives: The objective of this systematic review was to consolidate existing evidences on safety, immunogenicity and efficacy of RZV in immunocompromised adults aged 18-49 years. Methods: Four databases were searched. Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) guidelines were followed. Screening and classification of search items was performed using the web-based platform DistillerSR. Results: The search identified 1389 potentially relevant records. Six studies fulfilled inclusion criteria. The proportion of patients aged 18-49 varied between 23 and 62%. Pain at injection site (98.6%) and fatigue (75.3%) were the most common adverse events. The proportion of patients reporting serious adverse events (SAEs) ranged between 8.1 and 30.8% in RZV and between 4.1 and 36.5% in placebo groups. SAEs deemed related to vaccination were reported in < 1% of patients in both RZV and placebo groups. The proportion of patients that experienced clinically significant underlying disease-related events ranged between 0.0 and 20.0% in RZV and 0.0 and 26.7% in placebo groups. The humoral and cell-mediated immune response rate ranged between 65.4 and 96.2% and 50.0-93.0%, respectively. Vaccine efficacy in hematopoietic stem cell transplant patients was 72% (95%CI, 39-88%) in 18-49-year-olds and 67% (95%CI, 53-78%) in >= 50-year-olds (median follow-up 21 months). Vaccine efficacy in >= 18-year-old patients with hematologic malignancies was estimated at 87.2% (95%CI, 44.3-98.6%) up to 13 months post-vaccination. Conclusions: Results suggest that RZV has an acceptable safety profile and induces immunity in an important proportion of >= 18-year-old immunocompromised patients. Longer follow-up studies are warranted to assess the duration of RZV induced immunity in immunocompromised patients. (C) 2020 Elsevier Ltd. All rights reserved.