The most common autoimmune diagnoses included myositis (n=6) and inflammatory arthritis (n=3). Most (13/18) were women with median (IQR) age of 55 (44–63) years. We observed serial anti-spike antibody responses among these participants.Ī total of 18 participants received a booster SARS-CoV-2 vaccine dose ( table 1). Using our prospective cohort of patients with autoimmune disease, 5 we included patients who reported receipt of a single booster dose of SARS-CoV-2 mRNA or adenovirus vector vaccine between 10 April and 11 June 2021. Thus, we sought to describe the humoral response in patients with autoimmune disease who received a booster SARS-CoV-2 vaccine. 3 Recent studies have demonstrated enhanced humoral response to third-dose SARS-CoV-2 vaccination in immunosuppressed transplant patients, 4 5 but the immunogenicity of booster vaccination in other immunosuppressed populations is unknown. An attenuated humoral response to SARS-CoV-2 vaccination has been observed in some patients with autoimmune disease, 1 2 and immunosuppressed status has been associated with an increased risk of COVID-19 infection despite vaccination.