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)

ABSTRACT

Background: 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. Method(s) 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. Result(s) 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). Conclusion(s) 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.