Gabriella Bröms

During the COVID-19 pandemic, Sweden saw a rise in immune-mediated inflammatory diseases (IMIDs) such as inflammatory bowel disease, rheumatoid arthritis, asthma and psoriasis —a trend that has persisted beyond 2022. While viral infections may trigger IMIDs, the role of SARS-CoV-2 infection remains unclear. Emerging factors like mRNA vaccines, reduced social contact, and health care disruptions require investigation but are difficult to assess through clinical trials. The proposed research project leverages Sweden’s unique population registers and biobank data to explore links between SARS-CoV-2 infection, vaccination, social contact, and new-onset IMIDs. We will analyze data from 53 national registers in the SWECOV database (15.7 million individuals, 1990–2024), linked with repeated autoantibody measurements from the COMMUNITY cohort, which includes 2,267 individuals (2020–2024). Five substudies over 3 years will examine: (1) temporal trends in IMIDs (2) effects of SARS-Cov-2 infection by frequency/severity 3) COVID-19 vaccination effects by vaccine type/dose, (4) social isolation via occupation/household factors, and (5) immune markers (autoantibodies) pre- and post-infection or vaccination. This project will clarify mechanisms behind rising autoimmunity and improve our understanding of immunology and peripandemic disease trends, thereby informing clinical practice and public health policy e.g. the need for tailored follow-up care and surveillance.