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.