A 12-month follow-up study of patients with systemic lupus erythematosus after immunization against SARS-CoV-2.

Objective: To identify all post-BNT162b2 vaccination (BioNTech and Pfizer) events during the ensuing 12 months in patients with systemic lupus erythematosus (SLE) from the Immuno-Rheumatology Department at Cayetano Heredia Hospital's cohort, Lima, Perú.

Methods: A 12-month follow-up study was conducted from the first dose of immunization with the BNT162b2 vaccine, which was given between May and June 2021, to SLE patients from this cohort.

Results: The initial population was constituted by 100 patients (100 patients received the 1st dose, 90 the 2nd dose, and 85 the 3rd dose of this vaccine); 33 patients presented a SLE reactivation (flare), 9% (9/100) post 1st dose, 26.6% (24/90) post 2nd dose, and 16.4% (14/85) post 3rd dose. The most common types of flare were articular (26) and renal (14) with 5/33 (15.1%) requiring hospitalization for flare management. A negative association with flare occurrence was found between the use of hydroxychloroquine RR 0.43 (0.21-0.85) and the opposite was the case for azathioprine RR 2.70 (1.39-5.25). During follow-up, 26 patients developed SARS-CoV-2 infection of whom three required hospitalization, one of whom died.

Conclusions: 33 of 100 SLE patients immunized with BNT162b2 vaccine against SARS-CoV-2, presented SLE flares (47 episodes in total); 5 of these patients required in-hospital management and all fully recovered; 26 patients had SARS-CoV-2 infection; three required hospitalization, one died.