OP0176 THE PERSISTENCE OF ANTI-SPIKE ANTIBODIES FOLLOWING TWO SARS-CoV-2 VACCINES IN PATIENTS WITH IMMUNE-MEDIATED INFLAMMATORY DISEASES USING IMMUNOSUPPRESSIVE THERAPY, COMPARED TO HEALTHY CONTROLS

Background Limited data is available regarding long-term effectiveness of SARS-CoV-2 vaccines in patients with immune-mediated inflammatory diseases (IMIDs) on immunosuppressive therapy. Whether the persistence vaccine-induced humoral immunity against differs between this patient population and general public currently unknown. Objectives To compare anti-Spike antibodies following two vaccine doses IMID using medication healthy controls identify predictors antibody decline. Methods We included joint- bowel enrolled prospective observational Nor-vaC study. Serum samples were collected at time points dose vaccination (first assessment within 6–48 days second 49–123 days). Sera analysed for binding receptor-binding domain (RBD) Spike protein. Anti-RBD <200 BAU /ml defined as low levels. The estimated percent reduction anti-RBD standardised to 30 was calculated factors associated identified multivariable regression models. Results A total 1097 (400 rheumatoid arthritis, 189 psoriatic spondyloarthritis, 129 ulcerative colitis, 190 Crohn´s disease) (median age 54 years [IQR 43–64]; 56% women) 133 45 35–56]; 83% provided blood intervals 19 15–24] 97 [86–105] after dose). Antibody levels significantly lower compared both assessments, median 1468 BAU/ml 500–5062] 5514 [2528–9580] (p<0.0001) 298 79–500] 715 [28–2870] (p<0.0001), first respectively. Figure 1 show assessments group. At assessment, decreased below 200 452 (41%) (0.8%) control (Table 1). percentage change -86 % -77 (p<0.0001). majority rituximab had 1. In analyses, a greater decline β -3.7 (95% CI -6.0, -1.4) (p<0.001). Use tumor necrosis factor inhibitors mono- or combination therapy greatest controls, -6.1 -8.1, -4.1) -6.4 (-8.4, -4.2) respectively Table Serological response Controls (n=133 ) Patients (n=1097 (BAU/ml st 2 nd <5, n (%) 0 18 (1.6) (5) 5-19, 4 (0.4) 60 20-199, (1) 40 (4) 338 (31) 200-1999, 25 (19) 89 (67) 548 (50) 558 (51) 2000-8999, 71 (53) (30) 398 (36) 82 (7.5) ≥ 9000, 37 (28) 3 (2) (8) 5 (0.5) 6 - 48 49 -123 dose. BAU= Binding Units Conclusion Within four months dose, declined considerably controls. more pronounced consequently likely have Our results support that lose protection need additional sooner than individuals. Disclosure Interests Ingrid Egeland Christensen: None declared, Jyssum: Anne Therese Tveter: Joe Sexton: Trung T. Tran: Siri Mjaaland: Grete B. Kro: Tore K. Kvien Speakers bureau: Amgen, Celltrion, Egis, Evapharma, Ewopharma, Hikma, Oktal, Sandoz, Sanofi, Consultant of: Abbvie, Biogen, Eli Lilly, Gilead, Mylan, Novartis, Pfizer, Grant/research from: Grants institution (Diakonhjemmet Hospital): BMS, MSD, UCB, David Worren: Jørgen Jahnsen AbbVie, Astro Pharma, Boerhinger Ingelheim, Ferring, Janssen Cilag, Meda, Napp Orion Pharma Pharmacosmos, Roche, Takeda, Cilag Unimedic Ludvig A. Munthe Cellgene, Espen Haavardsholm: John Torgils Vaage: Gunnveig Grodeland Bayer, Sanofi Pasteur, Thermo Fisher, Consulting fees from Norwegian System Compensation AstraZeneca, Fridtjof Lund-Johansen: Kristin Kaasen Jørgensen Norgine, Silje Watterdal Syversen: Guro Løvik Goll Sella Aarrestad Provan: declared