Humoral and cellular immunity in patients with rare autoimmune rheumatic diseases following SARS-CoV-2 vaccination

Objectives: COVID-19 vaccine responses in rare autoimmune rheumatic diseases (RAIRD) remain poorly understood, in particular there is little known about whether people develop effective T-cell responses. We conducted a prospective cohort study to evaluate the short-term humoral and cell-mediated T-cell response after the second SARS-CoV-2 vaccination in RAIRD patients compared to healthy controls (HC).Methods: Blood samples were collected after the second dose and anti-spike, anti-nucleocapsid antibody levels and SARS-CoV-2 specific T-cell responses were measured and compared with HC. Activation induced marker and deep phenotyping assays were used to identify differences in T cells between high and low/no antibody groups, followed by multi-dimensional clustering.Results: 50 patients with RAIRD were included (31 with AAV, 4 with other systemic vasculitis, 9 with SLE and 6 with myositis). Median anti-spike levels were significantly lower in RAIRD compared to HC (p