ABSTRACT
IMPACT OF INFLAMMATORY BOWEL DISEASE THERAPIES ON DURABILITY OF HUMORAL RESPONSE TO SARS COV-2 VACCINATION Background and Aim: Immunization against the spike protein of SARS-CoV-2 reduces the risk of severe outcomes and previous data show that most inflammatory bowel disease (IBD) patients mount SARS-CoV- 2 anti-spike (S) antibodies (Ab). However, no data exist on the durability of these antibodies over time. We sought to investigate the impact of IBD and its therapies on post-vaccination antibody response and decay rates. Methods: Data were retrospectively ed from patients with IBD who underwent one Anti-S Total Ab (Labcorp®) test ≥2 weeks post 2nd dose, between April 15th-October 19th, 2021. Analyses included t-tests/1-way ANOVA, Mood's medians tests, chi-square and Fisher-exact tests. Linear regression estimated linear log(e)(Anti-S Total Ab) decays post-vaccine dose #2 (excluding patients with COVID-19 history). Exponentiated decay coefficients (EDC) represent % change from geometric mean titer (GMT). Results: We identified 176 patients with Anti-S Total Ab (Labcorp®) titer testing following two doses of the BNT162b2 (Pfizer/BioNTech;n=111) or mRNA-1273 (Moderna;n=65) vaccines. We compared non-immunosuppressed (IS) patients (non-anti- TNF biologics/Mesalamine/Budesonide/No therapy) to patients on IS (anti-TNF-a ± immunomodulators). Patients on systemic steroids (n=7) or tofacitinib (n=7) were excluded due to low sample size. Median interval from dose #2 to titer testing was 126 days (IQR:89-162), similarly distributed among vaccine/medication groups (p=0.4). Overall GMT was 306 u/ mL (95%CI 234-401), non-significantly different between vaccines (p=0.6). Four patients had undetectable antibodies (three on tacrolimus and one on renal dialysis). One had breakthrough COVID-19 infection (S-titer=13u/mL). Patients receiving IS had significantly lower titers (mean log) for both vaccines, compared to those without IS overall (Fig 1A). Patients receiving IS had lower proportions with Anti-S Total Ab above 100U/mL, 300 U/ mL, 500U/ml and 1000U/mL at all timepoints up to 6 months post-second dose (Fig 1B). Patients on IS had significant titer decay (Fig 1C, n=42, EDC 1.8%/day, p=0.012, t½≈38 days) and was significantly faster (Δ-slope p<0.05) than those not on IS (n=74, p=0.058, EDC 0.05%/day, t½≈153 days). Among anti-TNF monotherapy patients (Fig 1D), there was faster decay in BNT162b2 (n=25, EDC 2.4%/day, p=0.002, t½≈28 days) compared to mRNA- 1273 (n=10, EDC 0.9%/day, p=0.188, t½»76 days), with near-significant Δ-slope (p=0.109). Conclusions: While IBD patients initially exhibit robust responses to SARS-CoV-2 vaccination, far fewer patients on IS achieve high titers. Titers decay faster in those on anti-TNF agents, and data suggests this decay is more pronounced with BNT162b2 (Figure Presented)