P313 Within, 6 months from COVID-19 BNT162b2 vaccine patients with Inflammatory Bowel Diseases treated with Anti-TNFα have significantly lower serologic responses

Abstract

Background: While vaccines against COVID-19 are effective in healthy individuals, we reported significantly lower serologic responses to BNT162b2 in patients with inflammatory bowel diseases (IBD) treated with anti-tumor necrosis factor (TNF) alpha agents. As this was apparent already, 4 weeks post vaccination, vaccine longevity is concerning. Aim(s): to assess long-term serologic responses to BNT162b2 in patients with IBD stratified according to medical treatment. Method(s): A prospective, observational multi-center Israeli study. Patients with IBD (anti-TNFalpha treated versus non-anti-TNFalpha treated) and healthy controls (HC) were followed from before the, 1st BNT162b2 dose until, 6 months after vaccination. COVID-19 spike (S) and nucleocapsid (N) antibodies (Abs) concentrations were analyzed by ELISA, followed by neutralization studies. Specific anti-receptor binding domain (RBD) memory B-cells response, serologic responses against variants of concern (VOCs), Beta, Gamma and Delta, immunoglobulin levels and lymphocyte cell subsets were evaluated as well. Safety was assessed using questionnaires, clinical and laboratory data. Result(s): Of, 193 subjects, 130 had IBD (45 and, 85 in the anti-TNFalpha and non-anti-TNFalpha groups, respectively), 63 HC. Serologic response assessed, 176 (median) days (IQR, 166-186) and compared to, 4 weeks after, 1st dose significantly declined in all three groups, but was lowest in the anti- TNFalpha group:, 6 months anti-S Abs titer geometric means:, 193 (95%CI:, 128-292), 703 (520-951), and, 1253 (1023-1534) in anti-TNFalpha, nonanti- TNFalpha and HC groups, respectively, p<0.001, Figure, 1. This was further supported by neutralization and inhibition studies. Importantly, significantly decreased memory B-cell response towards RBD was detected only in the anti-TNFalpha group, with the most significant reduction in response to Beta VOC (p<0.0008 and p<0.0001, vs. non-anti-TNFalpha and HC, respectively). Older age was an additional predictor of lower serologic response. Immunoglobulin levels and lymphocyte cell subsets were comparable between the study groups. Infection rate reflected by anti-N Abs was ~1% in all groups. Safety was comparable in all groups. Conclusion(s): The, 6-months serologic response to BNT162b2 vaccine, evaluated prospectively, decreased in all subjects, most prominently in patients with IBD treated with anti-TNFalpha. Importantly, the latter also had the sharpest decline in serologies, the lowest functional activity and lowest RBD specific memory B-cells. Older age is an additional predictor of decreased serologic response. Altogether, waning of COVID- 19 serologic and functional response over, 6 months, specifically in patients with IBD treated with anti-TNFalpha, supports the need for an early third vaccine dose. (Figure Presented).