Objectives To study the safety and immunogenicity of a live-attenuated herpes zoster (HZ) vaccine in patients with systemic lupus erythematosus (SLE).

Methods Adult SLE patients having a SLEDAI <6 and stable immunosuppressive treatment for ≥6 months were recruited. Participants were randomly assigned to receive HZ vaccine (Zostavax) or placebo injection. Anti-varicella zoster virus (VZV) IgG reactivity (baseline and week 6) was measured by an enzyme-linked fluorescence assay. Cell-mediated response was assessed by a VZV-stimulated interferon-gamma (IFN-γ) enzyme-linked ELISPOT assay. Adverse events and immune responses of the two groups were compared.

Results 90 SLE patients were recruited (age 45.6±14.1 years; 93% women) and assigned to Zostavax or placebo (in 1:1 ratio). Baseline clinical parameters were similar between the two groups. The change in anti-VZV IgG from week 0 to 6 was +59.8% in the vaccine and −2.1% in the placebo group. Week 6 anti-VZV IgG was significantly higher in vaccinated than placebo-treated patients, after adjustment for baseline (4.16±1.26 vs 3.32±1.01; p<0.001). The number of IFN-γ secreting T-cell spots decreased in the placebo-treated patients (−17%) but increased in vaccinated patients (+42%). The T-cell spots number at week 6 was significantly higher in vaccine—than placebo-treated patients after adjustment for baseline (38.1±78.2 vs 23.1±47.9; p=0.02). Significantly more vaccinated patients reported self-limiting injection site reaction than controls (31% vs 7%; p<0.01). Two vaccinated patients (4.4%) and one (2.2%) placebo-treated patient had mild/moderate SLE flares but no patients developed HZ eruption within 6 weeks postvaccination.

Conclusions In patients with stable SLE not receiving intensive immunosuppression, Zostavax was well-tolerated and provoked an immune response.

Trial registration number US ClinicalTrials.gov registry (NCT02477150).