REDUCED SEROLOGICAL RESPONSE TO COVID-19 VACCINES IN PATIENTS WITH IBD IS FURTHER DIMINISHED BY TNF INHIBITOR THERAPY;EARLY RESULTS OF THE VARIATION STUDY (VARIABILITY IN RESPONSE IN IBD AGAINST SARS-COV2-IMMUNISATION)

ABSTRACT

Objective: Patients with inflammatory bowel disease (IBD) have attenuated responses to current vaccinations. There is a limited body of evidence suggesting patients with IBD receiving TNF antagonists have an attenuated response to vaccination against COVID-19. We sought to determine the impact of IBD and various medications for the treatment of IBD on antibody responses to vaccination against COVID-19. Design: Patients with IBD (n=270) and healthy controls (HC, n=116) were recruited prospectively and quantitative antibody responses assessed following COVID-19 vaccination. The impact of IBD and medications for treatment of IBD on vaccine response rates was investigated. Results: All HC seroconvert post complete vaccination with two vaccine doses [100%]. A small proportion of patients with IBD failed to seroconvert [2%]. Median anti-spike protein (SP) immunoglobulin (Ig)G levels post one vaccination and complete vaccination in our IBD cohort was significantly lower than HC [2,613 AU/mL versus 6,871 AU/mL, p=<0.001] [Figure 1]. A diagnosis of IBD was independently associated with lower anti-SP IgG levels [β coefficient -0.2, p = 0.001] whereas use of mRNA vaccines was independently associated with higher anti-SP IgG levels [β coefficient 0.25, p = < 0.001]. Patients with IBD receiving anti-TNF therapy had significantly lower anti-SP IgG levels [2444.6 AU/mL] than IBD patients not receiving these agents [3867.6 AU/mL] [p = < 0.001]. Patients with IBD not receiving TNF inhibitors still showed attenuated responses compared to HC receiving a similar vaccine [p = 0.001] [Figure 2]. 58 patients had an additional follow-up serology sample at a median of 12 weeks to complete vaccination to allow assessment of the durability of the response after their initial post-vaccination IgG level. There was a significant drop in IgG levels from 3952.85 AU/mL at the first timepoint checked post-complete vaccination to 921.1 AU/mL (343.1 – 2102.7) on follow-up sampling (p = <0.001). Median anti-SP IgG levels were numerically lower in our cohort receiving anti-TNF therapy (794.8 AU/mL) compared to those not receiving anti-TNF therapy (3136.9 AU/mL) on final follow-up samples (p =0.28). HC participants with previous COVID-19 infection (n= 5) had significantly higher anti-SP IgG levels post complete vaccination (20,719.6 AU/mL) compared to IBD patients (n=4) with prior infection (3,938.2 AU/mL) (p = < 0.001). Conclusions: Patients with IBD have attenuated serological responses to SARS-CoV-2 vaccination. Patients with IBD who do not seroconvert post-vaccination against COVID-19 are a particularly vulnerable cohort. Use of anti-TNF therapy negatively impacts anti-SP IgG levels. Impaired responses to vaccination in our study highlights the importance of booster vaccination programmes for patients with IBD. (Figure Presented) Differences in median IgG levels across three time points (Figure Presented) Differences in median anti-SP Levels dependent on medication for treatment of IBD.