Risk of autoimmune disease flares after recombinant zoster vaccine: A vaccine safety analysis based on the Vaccine Adverse Event Reporting System database.

Since its introduction in 2017, limited research has assessed the risk of flares in patients with autoimmune disease receiving the recombinant zoster vaccine (RZV). Herein, we evaluated the RZV-related flare risk using the Vaccine Adverse Event Reporting System (VAERS), exploring relevant patient characteristics. RZV vaccination records were extracted from VAERS (2017 Q1-2024 Q3), focusing on individuals diagnosed with rheumatoid arthritis (RA), multiple sclerosis (MS), inflammatory bowel disease (IBD), psoriasis, or systemic lupus erythematosus (SLE). RZV-related flare cases were identified using preferred terms and symptom descriptions. Disproportionality analyses, including reporting odds ratio (ROR) and three additional algorithms, were performed. Descriptive analyses assessed clinical characteristics and time to flare onset. A total of 920 patients who received RZV were identified, with a flare incidence of 8.5% (n = 78). Disproportionality analysis showed a positive flare risk signal (ROR, 3.00; P < .001). RORs for vaccine-related flares were 7.50 (SLE), 5.61 (MS), 5.03 (RA), 3.16 (psoriasis), and 2.07 (IBD). Except for the specific autoimmune disease, flare risk was not significantly associated with age, sex, or vaccine dose. Fifty-nine percent of flares occurred within 0-3 days post-vaccination. Symptom resolution was reported for 25.6% of flare cases, mostly (70%) spontaneous. Patients with autoimmune disease were at risk of RZV-related flares. Flare risk was highest risk for patients with SLE. Close monitoring within 3 days post-vaccination is advised. We provide VAERS-based evidence to support vaccine safety evaluation, guiding the clinical management of autoimmune disease.