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. This article is protected by copyright. All rights reserved.

Vaccine hesitancy is considered a major barrier to achieving herd immunity against COVID-19. While multiple alternative and synergistic approaches including heterologous vaccination, booster doses, and antiviral drugs have been developed, equitable vaccine uptake remains the foremost strategy to manage pandemic. Although none of the currently approved vaccines are live-attenuated, several reports of disease flares, waning protection, and acute-onset syndromes have emerged as short-term adverse events after vaccination. Hence, scientific literature falls short when discussing potential long-term effects in vulnerable cohorts. The COVAD-2 survey follows on from the baseline COVAD-1 survey with the aim to collect patient-reported data on the long-term safety and tolerability of COVID-19 vaccines in immune modulation. The e-survey has been extensively pilot-tested and validated with translations into multiple languages. Anticipated results will help improve vaccination efforts and reduce the imminent risks of COVID-19 infection, especially in understudied vulnerable groups.

Objectives We aimed to compare the spectrum and severity of COVID-19 and vaccine breakthrough infections (BIs) among patients with IIMs, other systemic autoimmune and inflammatory diseases (SAIDs), and healthy controls (HCs). Methods This is a cross-sectional study with data from the COVAD study, a self-reported online global survey that collected demographics, COVID-19 history, and vaccination details from April to September 2021. Adult patients with at least one COVID-19 vaccine dose were included. BIs were defined as infections occurring > 2 weeks after any dose of vaccine. Characteristics associated with BI were analyzed with a multivariate regression analysis. Results Among 10,900 respondents [42 (30–55) years, 74%-females, 45%-Caucasians] HCs were (47%), SAIDs (42%) and IIMs (11%). Patients with IIMs reported fewer COVID-19 cases before vaccination (6.2%-IIM vs 10.5%-SAIDs vs 14.6%-HC; OR = 0.6, 95% CI 0.4–0.8, and OR = 0.3, 95% CI 0.2–0.5, respectively). BIs were uncommon (1.4%-IIM; 1.9%-SAIDs; 3.2%-HC) and occurred in 17 IIM patients, 13 of whom were on immunosuppressants, and 3(18%) required hospitalization. All-cause hospitalization was higher in patients with IIM compared to HCs [23 (30%) vs 59 (8%), OR = 2.5, 95% CI 1.2–5.1 before vaccination, and 3 (18%) vs 9 (5%), OR = 2.6, 95% CI 1.3–5.3 in BI]. In a multivariate regression analysis, age 30–60 years was associated with a lower odds of BI (OR = 0.7, 95% CI 0.5–1.0), while the use of immunosuppressants had a higher odds of BI (OR = 1.6, 95% CI 1.1–2.7). Conclusions Patients with IIMs reported fewer COVID-19 cases than HCs and other SAIDs, but had higher odds of all-cause hospitalization from COVID-19 than HCs. BIs were associated with the use of immunosuppressants and were uncommon in IIMs.