OP0175 TYPE OF mRNA COVID-19 VACCINE AND TREATMENT INFLUENCE ANTIBODY KINETICS IN PATIENTS WITH INFLAMMATORY RHEUMATIC DISEASES

Background Patients on immunomodulatory treatments mount an attenuated immune response following mRNA COVID-19 vaccination, yet long-term studies of vaccine-induced anti-SARS-CoV-2 antibody (Ab) kinetics are missing. Objectives In this prospective observational study, we mapped the humoral to vaccines up 24 weeks post full vaccination in patients with inflammatory rheumatic diseases (IRDs). We aimed assess differences due treatment, age, past SARS-CoV-2 infection, and vaccine (BNT162b2 vs. mRNA-1273). Methods Adult from SCQM cohort who assented were recruited between 3/21 – 9/21. Participants answered questionnaires via app received kits for self-collection capillary blood samples at baseline, 4, 12, vaccination. Samples tested IgG Ab against S1 domain spike protein (anti-S1-IgG) using EUROIMMUN ELISA. To examine titres arising defined parameters, while accounting inter-assay variability, mixed effects continuous outcome logistic regression models applied each timepoint. Results obtained 570 patients: 67% female, mean age 53 y (SD 12 y) 37% RA, 36% axSpA, 21% PsA, 6% UA (undifferentiated arthritis), no medication (no DMARDs & glucocorticoids; 15%), csDMARDs (10%), TNFi (48%), IL-1/6/17/23i (14%), JAKi (6%), rituximab (RTX; 4%), or abatacept (ABA; 2%) mono/combination therapy first 10% had a 54% BNT162b2, 46% mRNA-1273. For any threshold, odds having higher titre 3.3 4 times mRNA-1273 compared BNT162b2 (Table 1, Figure 1). TNFi, JAKi, RTX, ABA as monotherapy resulted significantly lower levels almost all timepoints. combination therapy, IL-1/6/17/23i, led consistently timepoints respective monotherapy. Table 1. The OR being above given regardless threshold. Ref. levels: medication, inf., BNT162b2. Included model but not shown: diagnosis, infrequently used (all non-signif.) Weeks vacc. (95% CI); p Age 0.96 (0.94 0.97) **** 0.98 (0.96 0.996) * (0.97 1.00) (vs BNT162b2) 3.28 (2.34 4.61) 3.96 (2.83 5.54) 3.94 (2.93 5.50) Past COVID inf. none) 7.56 (4.32 13.2) 8.14 (4.78 13.86) 11.65 (6.62 20.50) csDMARD † 1.27 (0.67 2.41) 1.78 3.35) 1.70 (0.86 3.36) 0.46 (0.28 0.71) 0.30 (0.19 0.48) 0.13 (0.081 0.22) 0.97 (0.54 1.75) 1.04 (0.57 1.89) 0.89 (0.49 1.64) 0.38 (0.16 0.91) 0.53 (0.22 1.28) RTX 0.078 (0.013 0.46) ** (0.015 0.42) 0.16 (0.037 0.14 (0.039 0.51) 0.087 (0.022 0.35) *** 0.068 (0.017 0.27) Interactions § Age:vaccine ‡ (1.02 1.07) 1.02 (0.99 1.05) 1.03 (1.0008 1.058) csDMARD:combi 0.12 (0.02 0.70) 0.17 (0.029 0.95) 0.11 (0.023 0.56) TNFi:combi 0.34 (0.20 0.59) 0.37 0.61) 0.36 (0.21 0.62) IL-1/6/17/23i:combi 0.26 (0.09 0.78) 0.25 (0.085 0.20 (0.071 0.58) JAKi:combi 1.76 (0.33 9.44) 1.23 (0.32 4.70) 0.95 (0.25 3.65) RTX:combi (0.01 0.87) 0.095 (0.012 0.73) 0.085 (0.0091 0.79) ABA:combi 1.75 12.2) 0.74 (0.096 5.75) 0.51 (0.073 3.62) < 0.05; 0.01; 0.001; 0.0001; Medication monoth. vs Interaction terms showing how increases medications: th. Conclusion Compared some therapies markedly IRD patients, infection strikingly increased immunogenicity, did Acknowledgements This study is investigator-initiated independent financial support Moderna Switzerland GmbH. thanks their participation study. A list rheumatology offices hospitals that contribute registries can be found www.scqm.ch/institutions . financially supported by pharmaceutical industries donors. supporters www.scqm.ch/sponsors Disclosure Interests Catherine Elizabeth Raptis Grant/research from: presented abstract , Diego Olivier Andrey: None declared, Christos Polysopoulos Christoph Berger: Adrian Ciurea: Pierre Lescuyer: Tanja Maletic Myriam Riek Almut Scherer Isabell von Loga Judith Safford: Kim Lauper Speakers bureau: reports consulting fees Pfizer speakers Pfizer, Viatris Celltrion outside submitted work., Consultant of: Burkhard Moeller: Nicolas Vuilleumier: Axel Finckh has consultancies speaker honoraria AbbVie, BMS, Eli-Lilly, Gilead, Sanofi, UCB work, research Galapagos, Andrea Rubbert-Roth: declared