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

To provide insight into the safety of recombinant zoster vaccine (RZV) in patients with immune-mediated inflammatory diseases (IMID). 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. 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]. 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.