To Örebro University

INTRODUCTION/AIMS: We studied COVID-19 vaccination-related adverse events (ADEs) 7-days post-vaccination in patients with idiopathic inflammatory myopathies (IIMs) and other systemic autoimmune and inflammatory disorders (SAIDs).

METHODS: 7-day vaccine ADEs were collected in an international patient self-reported e-survey. Descriptive statistics and multivariable regression were performed.

RESULTS: 10,900 respondents [1227 IIMs; 4640 SAIDs; 5033 healthy controls (HCs), median age 42 (IQR 30-55) years, 74% female, 45% Caucasian, 69% completely vaccinated] were analysed. 76.3% IIMs patients reported minor and 4.6% major ADEs. Patients with active IIMs reported more frequent major [OR 2.7 (1.04-7.3)] and minor [OR 1.5 (1.1-2.2)] ADEs than inactive IIMs. Rashes were more frequent in IIMs [OR-2.3(1.2-4.2)] than HCs. ADEs were not impacted by steroid dose, although hydroxychloroquine and intravenous/subcutaneous immunoglobulins were associated with a higher risk of minor ADEs [OR 1.9 (1.1-3.3), OR 2.2 (1.1-4.3)]. Overall, ADEs were less frequent in inclusion body myositis (IBM) and BNT162b2 (Pfizer) vaccine recipients DISCUSSION: 7-day post-vaccination ADEs were comparable in patients with IIMs, SAIDs, and HCs, except for a higher risk of rashes in IIMs. Patients with DM, active disease may be at higher risk, and IBM patients at lower risk of specific ADEs. Overall, the benefit of preventing severe COVID-19 through vaccination likely outweighs the risk of vaccine-related ADEs Our results may inform future guidelines regarding COVID-19 vaccination in patients with SAIDs, and specifically in IIMs. Studies to evaluate long-term outcomes and disease flares are needed to shed more light on developing future COVID-19 vaccination guidelines.