P330 Immunity in patients with inflammatory bowel disease on biologic therapy after COVID, 19 vaccination

Background IBD patients, especially on immunosuppressive therapy, are in high-risk of developing infections, the outbreak of the SARS-CoV-2 pandemic, made us approach to the whole situation with special caution. At beginning, we wondered if these patients were at increased risk of developing severe COVID19 infection. Knowledge and experience, in this area have progressed, however, with the beginning of vaccination a new question has arisen about what the humoral response to the vaccine would be in these patients. In Serbia, 3 different types of vaccines from, 4 manufacturer (Pfizer-BioNTech, AstraZeneca/ ChAdOxl nCoV-l9 COVISHIELD, SARS-CoV-2 Vero Cell, SPUTNIK V Gam-COVID-Vac) were available and the aim was to evaluate presence of neutralization antibodies after immunization against SARS-CoV-2. Methods 328 patients with IBD, from a single tertiary IBD center, were asked about immunization against SARS-CoV-2 during treatment with biologic therapy (anti-TNF, anti-integrin- Vedolizumab) with two doses of available vaccines. Patients who were immunized were selected and analyzed on SARS-Cov-2 IgG response which was measured using ELISA anti-spike protein-based serology (INEP, Belgrade, Serbia) with cut off level of, 15 as negative, 15–20 intermediate, and >, 20 as positive. Results From, 328 patients, 61.5% (202/328) patients had CD, and, 38.1% (125/328) had UC. Gender distribution was relatively equal, 53.6% men (176/328), with an average age of, 55.7 (SD ±15.1) years. From those patients, 25 were excluded because biologic therapy was stopped. On ADA were, 105 patients, IFX were, 91, VDZ, 106. From, 303 patients, 58.08% (176/303) were vaccinated (with Pfizer-BioNTech COVID-19, 59 patients, AstraZeneca/ChAdOxl nCoV-l9 COVISHIELD, 9 patients, SARS-CoV-2 Vero Cell, 97 patients and SPUTNIK V Gam-COVID-Vac, 11 patients). In, 16 patients IgG antibodies weren’t measured because they were vaccinated after IgG were measured. From, 160 patents, 31.2 % (50/160) didn’t have detectable IgG antibodies and that is in, 5 patients vaccinated with Pfizer-BioNTech COVID-19, 43 patients with SARS-CoV-2 (Vero Cell) and in, 2 patients with SPUTNIK V Gam-COVID-Vac. When we look in contest of therapy. IgG antibodies were detectable in, 53.9% (34/63) from, 63 vaccinated patients on VDZ and in, 53.06% (52/98) from, 98 vaccinated patients on anti TNF. Conclusion In patients with inflammatory bowel disease on biologic therapy from February to September, 2021 rate of immunization were satisfying with more than, 50% vaccinated patients with detectable IgG antibodies in, 68.6% of patients with highest neuralization IgG antibodies present after immunization with Pfizer-BioNTech COVID-19 vaccine, however further studies are needed to determine efficacy of each vaccine.