P755 Impaired antibody seroconversion after COVID-19 vaccination and negative impact of immunosuppressive treatment in Inflammatory Bowel Disease. Results from a multicentre, prospective study of GETECCU (VACOVEII).

Julián, A.B.(1)*;Casas-Deza, D.(1);Vicente-Lidón, R.(1);Beltrán, B.(2);Domènech, E.(3);Gutiérrez-Casbas, A.(4,5);Mañosa, M.(3);Zabana, Y.(5,6);Caudevilla-Biota, E.(7);Corsino-Roche, P.(1,7);Sierra-Moros, E.(1);Franco-Fobe, L.E.(8);Pina-Echevarría, S.(8);García-González, E.(9);Alfambra, E.(7,10);Gargallo-Pueyo, C.(7,10);Sicilia, B.(11);Arias, L.(11);Alcala-Escriche, M.J.(12);Madero-Velázquez, L.(4);Ferreiro-Iglesias, R.(13);Palmero-Pérez, A.(14);Calafat, M.(3,5);Rubio-Iturria, S.(15);Moraleja-Yudego, I.(16);Ber-Nieto, Y.(17);García-Mateo, S.(10);P. Gisbert, J.(5,18,19);Barreiro-de Acosta, M.(13);García-López, S.(1,7);

(1)Hospital Universitario Miguel Servet, Gastroenterology, Zaragoza, Spain;(2)Hospital Universitari i Politècnic La Fe, Gastroenterology, Valencia, Spain;(3)Hospital Universitari Germans Trias i Pujol, Gastroenterology, Badalona, Spain;(4)Hospital General Universitario Doctor Balmis, Gastroenterology, Alicante, Spain;(5)Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Gastroenterology, Madrid, Spain;(6)Hospital Universitari Mútua Terrassa, Gastroenterology, Tarrassa, Spain;(7)Instituto de Investigación Sanitaria de Aragón, Gastroenterology, Zaragoza, Spain;(8)Hospital Universitario Miguel Servet, Microbiology, Zaragoza, Spain;(9)Hospital Universitario Miguel Servet, Biochemistry, Zaragoza, Spain;(10)Hospital Clínico Lozano Blesa, Gastroenterology, Zaragoza, Spain;(11)Hospital Universitario de Burgos, Gastroenterology, Burgos, Spain;(12)Hospital Obispo Polanco, Gastroenterology, Teruel, Spain;(13)Hospital Clínico Universitario de Santiago de Compostela, Gastroenterology, Santiago de Compostela, Spain;(14)Hospital Royo Villanova, Gastroenterology, Zaragoza, Spain;(15)Hospital Universitario de Navarra, Gastroenterology, Pamplona, Spain;(16)Hospital de Galdakao-Usansolo, Gastroenterology, Galdakao, Spain;(17)Hospital San Jorge, Gastroenterology, Huesca, Spain;(18)Hospital Universitario de La Princesa, Gastroenterology, Madrid, Spain;(19)Instituto de Investigación Sanitaria Princesa, Gastroenterology, Madrid, Spain; GETECCU


COVID-19 vaccination has been suggested as very effective in patients with Inflammatory Bowel Disease (IBD), but most studies assess antibody levels within a few weeks after vaccination and do not use the most recent recommendations as seroconversion cut-off. The objective of VACOVEII study is to evaluate the antibody response to vaccination at 6 months using these recommendations, the improvement after a booster dose and the effect of the immunosuppressive therapy (IST). We present the intermediate results of the study.


Spanish multicentre, prospective and case-control study. 18 years or older IBD patients fully vaccinated against COVID-19 were included. Those with previous COVID infection were not included, but not excluded for the next analyses if the infection was subsequent. Main outcomes were anti-SARS-CoV-2 spike protein antibody (anti S) concentrations and rate of seroconversion (defined above the protection threshold of 260 BAU/mL), measured 6 months after vaccination at a single centralized laboratory. The effect of IST on the main outcomes was analysed, adjusted by age, vaccine type and COVID infection. Groups of treatment considered for the analysis were: patients without IST (without treatment or under salicylates alone), anti-TNF in combination with immunomodulators (IMM), anti-TNF in monotherapy, IMM in monotherapy, ustekinumab and anti-integrin.


We included 313 patients with IBD (46.5% ulcerative colitis and 52.3% Crohn’s disease, median age 49 years) vaccinated either with non-mRNA vaccines (14%) or mRNA vaccines (86%). Baseline therapy was: 124 patients without IST, 21 with anti-TNF plus IMM, 67 with anti-TNF in monotherapy, 54 with IMM in monotherapy, 28 with ustekinumab and 19 with anti-integrin. Mean anti S concentrations were significant lower in patients with anti-TNF compared with patients without IST (Figure 1). In multivariable analysis, lower antibody concentrations were independently associated with anti-TNF treatment, non-mRNA vaccines and older age. Within the patients with no COVID infection during the follow-up, we found very low rates of seroconversion in patients with anti-TNF (14.1%), ustekinumab (30.8%) and IMM in monotherapy (34.9%), compared with patients without IST (51.5%) (Table 1). In multivariable analysis, anti-TNF treatment, non-mRNA vaccines and older age were independently associated with lower rates of seroconversion, as well as ustekinumab and IMM in monotherapy (Table 2).


COVID-19 vaccine-induced antibody seroconversion in patients with IBD, measured at 6 months and according to >260 BAU as protection threshold, is clearly lower than previously reported, with a profound impact by some IST therapies, mainly anti-TNF, besides age and type of vaccine.