Incidence, features and outcome of disease relapse after COVID-19 vaccination in patients with idiopathic inflammatory myopathies.

Abstract

Vaccination against coronavirus disease (COVID-19) is relatively safe in patients with idiopathic inflammatory myopathies (IIM), however, myositis flares following vaccination have been poorly studied. We aimed to evaluate the frequency, features and outcomes of disease relapses in patients with IIM following COVID-19 vaccination. A cohort of 176 IIM patients were interviewed after the 3rd wave of the COVID-19 pandemic and followed prospectively. Relapses were determined using the disease state criteria and the outcome of the flares with myositis response criteria, calculating the total improvement score (TIS). A total of 146 (82.9%) patients received a vaccination, 17/146 (11.6%) patients had a relapse within 3 months, and 13/146 (8.9%) patients within one month. The relapse rate of unvaccinated patients was 3.3%. Three months after the post-vaccination relapses, 70.6% of the patients (12/17) achieved an improvement of disease activity (average TIS score: 30±15.81; 7 minor, 5 moderate and 0 major improvements). Six months after flares improvement was detected in 15/17(88.2%) of relapsed patients (average TIS score: 43.1±19.53; 3 minimal, 8 moderate and 4 major). Forward stepwise logistic regression analysis revealed that the active state of myositis at the time of injection (p<0.0001; OR:33; CI:9-120) was significantly associated with the occurrence of a relapse. A minority of the vaccinated IIM patients had a confirmed disease flare after COVID-19 vaccination and the majority of the relapses improved after individualized treatment. An active disease state at the time of vaccination probably contributes to the increased risk of a post vaccination myositis flare. This article is protected by copyright. All rights reserved.