AB1336 EVALUATION OF THE IMMUNOGENICITY AND EFFICACY OF THE SARS-CoV-2 VACCINE IN PATIENTS WITH CHRONIC INFLAMMATORY DISEASES TREATED WITH BIOLOGICAL THERAPY

Background Data on the immunogenicity and efficacy of vaccines against COVID-19 in patients with chronic inflammatory diseases (CID) are uncertain and possibly lower than those observed in the general population, but the potential for severe COVID-19 in this population warrants their use. Objectives To determine the seroconversion rate and efficacy after the complete vaccination regimen against SARSCoV-2 in patients with CID on bDMARD treatment, as well as to evaluate the infection rate after vaccination and adherence to vaccination regimens. Methods Single-center, prospective observational study of 114 patients with CID from the HURS of Córdoba, who have received full vaccination for SARS-CoV-2 in 2021 (without having previously suffered from COVID-19 disease) according to national guidelines with a 12-month follow-up after vaccination. All of them underwent two determinations of specific IgG antibodies against the trimeric spike protein of SARS-Cov2 (2021 and 2022). It has been established that an Ab titer of less than 260 BAU/ml can be considered indicative and indicative of a poor response to vaccination. Information was collected for each patient regarding IHD, type of bDMARD, vaccine administered, concomitant treatments, adverse effects, and infection after vaccination. Results 114 patients were included (mean age 50 years, 67.5% women). 36% of the patients had RA, 12.3% SpA, 9.6% PSO, 28.9% IBD, and 13.2% other CID. 16.7% were receiving treatment with Rituximab, 36.8% anti-TNF, 9.6% Tocilizumab, 7% abatacept, 4.5% anti-JAK, and 6.1% other treatments. 19.3% only with synthetic Fame. Anti-SARS-CoV-2 antibodies and neutralizing activity were detected in 80% of study participants. Rituximab-treated patients showed significantly higher non-seroconversion (73.7% vs. 5.3%, p<0.001) (Figure 1) as well as a 58-fold higher risk of non-seroconversion compared to patients without bDMARDs (OR: 58.80 CI (8.86 - 120.4) p<0.001. Interestingly, we found that methotrexate alone also decreased seroconversion significantly (mean Ab titer reduction -654.6 (95%CI -1127.7 to -181.4, p=0.007). Furthermore, we observed a significant interaction between the type of biologic and the concomitant use of methotrexate, such that the reduction in the antibody titer is enhanced by the combination of methotrexate and anti-TNF, anti-IL 6, Rituximab, and other DMARDsb (Figure 2). 18.9% presented mild adverse effects after the administration of the vaccine.17.5% presented covid-19 infection during the last year of follow-up, being more frequent in the group vaccinated with Astrazéneca, although without statistically significant differences. No patient experienced a disease flare. In relation to adherence to vaccination, slightly more than half (56.14%) have administered at least 4 doses. Conclusion Our results show that mRNA vaccines against SARSCoV-2 produce seroconversion in the majority of patients with CID, except in the case of patients with rituximab. No serious adverse effects or ICD reactivation were found. Despite the small number of patients included, this study suggests the need for revaccination and the use of other vaccination strategies in the group of patients treated with rituximab and in the group of patients taking methotrexate. Efforts should be made to improve adherence to covid 19 vaccination in this group of patients. Figure 1. Shows how the use of rituximab is significantly associated with not developing antibodies. Figure 2. Represents the interaction between the biological drug and the use of methotrexate in relation to the level of Antibodies. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests None Declared.