Response to COVID-19 Vaccines in Patients with Inflammatory Bowel Disease and the Impact of Tumour Necrosis Factor Inhibitor therapy on Vaccine Response

In this thesis, I thoroughly evaluate and describe the immune response of patients with inflammatory bowel disease (IBD) to COVID-19 vaccination. This entails an extensive examination of immune response post vaccination examining anti-spike-protein immunoglobulin G levels, angiotensin converting enzyme 2 concentration and memory B cell response to the RBD and S antigens. The prevalence of COVID-19 infection in patients with IBD was also examined through assessing patients IgG nucleocapsid (NC) antibody levels. Particular attention is paid to the impact of different medications for treatment of IBD on response to COVID-19 vaccination and the impact of patient’s drug levels for those treated with anti-tumour necrosis factor agents on anti-SP IgG levels. I also examine the impact of micronutrient deficiencies including zinc, copper, selenium and selenium transporters such as selenoprotein P (SELENOP) and glutathione peroxidase 3 (GPx3) concentrations on antibody response to COVID-19 vaccination and the prevalence of COVID-19 infection. Pertinent findings from my thesis include the following:
• Vaccine response post COVID-19 vaccination is attenuated in patients with IBD
• Use of anti-TNF agents further attenuates vaccines response post COVID-19 vaccination in patients with IBD
• Higher drug levels of anti-tumiur necrosis factor (TNF) agents negatively impact antibody response to COVID-19 vaccination
• Although zinc, copper, ferritin, selenium or GPx3 concentration do not appear to impact vaccine response to COVID-19 vaccination or the prevalence of COVID-19 infection, lower SELENOP levels negatively impact

COVID-19 vaccine response and is associated with a higher prevalence of COVID-19 infection
Overall we have shown clearly, as seen with other established vaccinations, patients with IBD have reduced response to COVID-19 vaccination with reduced anti-SP IgG levels and reduced memory B cell response to the RBD and S antigens. Overall we have concluded patients with IBD in particular patients receiving anti-TNF therapy for management of their IBD are a particular vulnerable cohort with reduced vaccine response to COVID-19 and should be counselled annually on the importance of booster vaccinations against COVID-19.