Effectiveness and safety of the recombinant zoster vaccine in adult patients with systemic lupus erythematosus: a claims-based retrospective cohort study in the USA

Abstract

Objectives: To assess vaccine effectiveness (VE) and safety of the recombinant zoster vaccine (RZV) in adults with systemic lupus erythematosus (SLE).

Methods: This retrospective study using administrative claims data collected between 1 January 2018 and 30 September 2023 from the USA included two cohorts of adults aged ≥18 years with SLE insured by (1) Medicare (parts A/B/D) or (2) one of five commercial partners (including Medicare Advantage plans). In VE analyses, adults receiving two RZV doses ≥28 days apart were matched 1:4 to unvaccinated comparators on insurer, sex and age (±5 years); the outcome was incident herpes zoster (HZ) after 31 days. In safety analyses, adults receiving RZV dose 1 or 2 were matched to unvaccinated comparators as above; the outcome was severe SLE flare within 90 days. Adjusted hazard ratios (HRs) were estimated using Cox models with inverse probability of treatment weighting (IPTW).

Results: VE cohorts included 2284 Medicare and 1308 commercially insured RZV-vaccinated patients; mean weighted follow-up was 1.4-1.6 person-years. Safety cohorts included 6602 RZV vaccinations (dose 1 or 2) in Medicare and 4196 in commercial insurers. Vaccinated versus unvaccinated patient characteristics were balanced after IPTW. VE was 70% (95% CI: 50% to 82%) in Medicare and 54% (95% CI: 18% to 74%) in commercially insured patients. The HR of severe SLE flare in vaccinated versus unvaccinated patients was 0.91 (95% CI: 0.75 to 1.11) in Medicare and 0.94 (95% CI: 0.72 to 1.24) in commercially insured patients.

Conclusions: RZV prevented a majority of HZ cases in individuals with SLE without increasing the risk of severe SLE flare.

Keywords: Epidemiology; Lupus Erythematosus, Systemic; Vaccination.

Figure 1. Study design. In VE analyses, follow-up started on day 31 post-index date to allow time for the development of immunity in RZV-vaccinated individuals. The same unvaccinated patients can serve as comparators for both the RZV dose 1 and RZV dose 2 safety cohorts.

1 Matched by sex, age ± 5 years, and insurer (for commercially insured population only) 2 HZ definition is based on an algorithm validated by Baxter et al. 3 Severe SLE flare definition is based on the algorithm published by Garris et al, with rituximab administration added as a criterion. HZ, herpes zoster; RZV, recombinant zoster vaccine; SLE, systemic lupus erythematosus; YOA, years of age; ZVL, live attenuated zoster vaccine.

Figure 2. Plain language summary.

Figure 3. Effectiveness of two RZV doses in patients with SLE for the prevention of HZ, results of weighted analyses—effectiveness cohort. All numbers reflect trimmed and inverse probability of treatment-weighted analyses, with 1% wt truncation for commercial data. HZ, herpes zoster; IR, incidence rate; RZV, recombinant zoster vaccine; SLE, systemic lupus erythematosus; VE, vaccine effectiveness.

Figure 4. Safety of RZV doses in patients with SLE in terms of severe SLE flares in the 90 days following RZV, results of weighted analyses—safety cohorts. All numbers reflect trimmed and inverse probability of treatment-weighted analyses. IR, incidence rate; RZV, recombinant zoster vaccine; SLE, systemic lupus erythematosus.