Predictors of Hospitalization in Breakthrough COVID-19 among Fully Vaccinated Individuals with Immune-Mediated Rheumatic Diseases: Data from SAFER-Study.

Breakthrough COVID-19 (occurring in fully vaccinated people) has been described. Data on its characteristics among immune-mediated rheumatic disease (IMRD) patients are scarce. This study describes breakthrough COVID-19 occurring in IMRD patients participating in the SAFER-study, a Brazilian multicentric cohort evaluating the safety, effectiveness, and immunogenicity of SARS-CoV-2 vaccines in patients with autoimmune diseases. A descriptive analysis of the population and a binary logistic regression model were performed to evaluate the predictors of COVID-19-related hospitalization. A -value < 0.05 was significant. The included 160 patients were predominantly females (83.1%), with a mean (SD) age of 40.23 (13.19) years. The patients received two (19%), three (70%), or four (11%) vaccine doses. The initial two-dose series was mainly with ChAdOx1 (Oxford/AstraZeneca) (58%) or BBIBP-CorV (Sinopharm-Beijing) (34%). The first booster (n = 150) was with BNT162b2 (BioNtech/Fosun Pharma/Pfizer) (63%) or ChAdOx1 (29%). The second booster (n = 112) was with BNT162b2 (40%) or ChAdOx1 (26%). The COVID-19 hospitalization rate was 17.5%. IMRD moderate/high activity (OR: 5.84; CI: 1.9-18.5; = 0.002) and treatment with corticosteroids (OR: 2.94; CI: 1.02-8.49; = 0.0043) were associated with higher odds of hospitalization, while increasing the number of vaccine doses was protective (OR: 0.37; CI: 0.15-0.9; = 0.032). These findings, along with previous reassuring results about the safety of the COVID-19 vaccines, argue in favor of booster vaccination in IMRD patients.