The Flare-up of Rheumatic Autoimmune Diseases Following COVID-19 Vaccination

Background: Individuals with Autoimmune Rheumatic Disease (AIRD) are vulnerability to severe SARS-CoV-2 outcomes and vaccination. The present study aimed to determine the incidence of AIRDs flares following COVID-19 vaccination and its risk factors. Methods: The study was retrospective cross-sectional focused on patients with AIRD who experienced a flare-up at least during 30 days after receiving the COVID-19 vaccine. These patients were seen at Rheumatology Clinics at Imam Reza and Ghaem Hospitals, affiliated with Mashhad University of Medical Sciences, as well as private clinics in Mashhad, Iran, over a period of 1 years. Results: The rate of recurrence following COVID-19 vaccination was estimated to be 3.16%. Rheumatoid arthritis (18.9%), systemic lupus erythematosus (12.9%), and cutaneous vasculitis (10.6%) were the most frequent AIRDs among patients who experienced a flare-up following COVID-19 vaccination. More than 85% of patients who were vaccinated with AstraZeneca experienced a flare-up after the first dose of vaccination. In the majority of patients, the flare-up occurred after the first dosage of COVID-19 vaccination. Conclusion: In Mashhad, Iran, the incidence of flare-ups in autoimmune and inflammatory rheumatic diseases following COVID-19 vaccination is estimated to be a mere 3%. Despite their rarity, flare-ups in autoimmune and inflammatory rheumatic diseases post-COVID-19 vaccination can still pose a public health issue, potentially undermining public confidence in vaccinations.