Safety of recombinant zoster vaccine: a retrospective study of 622 rheumatology patients

Objectives. To provide insight into the safety of recombinant zoster vaccine (RZV) in patients with immunemediated inflammatory diseases (IMID). Methods. Patients who received RZV in a single-centre rheumatology department were retrospectively included. An IMID flare was defined as (i) a documentation of flare in the office notes or patient portal communication or (ii) new prednisone prescription, in the 12 weeks after each dose. Results. Six-hundred and twenty-two patients were included (67% female, median age 67 years), 8.5% of them experienced adverse events (AEs) and herpes zoster (HZ) incidence was 0.6% after median follow-up of 36 weeks. Of 359 IMID patients: 88 had RA (25%), 50 vasculitis (14%) and 29 PMR (8%). At vaccination, 35% were on glucocorticoids (GC). Fifty-nine patients (16%) experienced a flare, 18 flares occurred in temporal relation to a treatment change (31%). RA patients had the highest flare rate (n = 21, 24%), 25% of patients who flared required adjustment of immunosuppression. In a multivariate analysis, use of GC at time of vaccination was associated with flare after vaccination [odds ratio (OR) 2.31 (1.3-4.1), P = 0.004]. A time-to-flare survival analysis (Cox-model) showed that GC was a significant predictor of IMID flare after first RZV dose [hazard ratio (HR) 2.4 (1.3-4.5), P = 0.0039] and that a flare after the first dose was associated with flaring after the second RZV dose [HR 3.9 (1.7-9), P = 0.0015]. Conclusion. RZV administration in patients with IMIDs was generally well-tolerated, though mild flares were not uncommon in the first 12 weeks after vaccination. These data may provide useful information for patient education when considering RZV administration.