Ulcerative Colitis (UC) is a chronic inflammatory bowel disease causing inflammation and ulcers in the lining of the large intestine. It is considered an autoimmune disease where the immune system mistakenly attacks healthy cells in the gastrointestinal tract. For individuals managing UC, the COVID-19 pandemic raised concerns about vaccine safety and effectiveness, especially since many UC treatments involve immune-modifying therapies. Understanding the scientific consensus is important for UC patients to make informed health decisions.
Safety of the Vaccine and Risk of UC Flare
Studies indicate that COVID-19 vaccination is safe for people with Ulcerative Colitis and does not significantly increase the risk of a disease flare-up. Large-scale registry data shows no association between receiving the vaccine and an increased rate of UC flares across the entire vaccine series. This provides reassurance that the vaccination process itself does not destabilize the disease.
Some UC patients report a temporary increase in gastrointestinal symptoms, such as diarrhea or abdominal pain, following vaccination. These symptoms are generally short-lived and do not constitute a true disease exacerbation. Minor side effects, including fatigue and fever, are similar to those experienced by the general population. The risk of a severe UC flare after vaccination is low, estimated to be between 2% and 4%.
The protective benefits of the COVID-19 vaccine outweigh the minimal risk of a flare. UC patients, especially those on immunosuppressant therapy, are at a higher risk for severe illness and complications if they contract COVID-19. Vaccination is recommended to protect against serious outcomes like hospitalization or death.
How UC Medications Affect Vaccine Efficacy
While the COVID vaccine is safe for UC patients, some medications used to manage the disease can affect the strength of the immune response, or vaccine efficacy. UC treatments aim to dampen the overactive immune system, which can result in a reduced ability to produce protective antibodies after vaccination. The degree of this reduction varies significantly by medication class.
Biologic Therapies
Biologic therapies, such as anti-tumor necrosis factor (anti-TNF) agents like infliximab, may result in lower antibody concentrations compared to those not on immune-modifying drugs. However, other biologics, such as vedolizumab, which works more selectively in the gut, have been associated with a more robust antibody response. Despite potentially lower antibody levels, reduced efficacy does not mean zero protection, and many patients on biologics still mount a positive immune response, especially after multiple doses.
Conventional Immunosuppressants
Conventional immunosuppressants, including thiopurines like azathioprine, and Janus kinase (JAK) inhibitors like tofacitinib, are also associated with a diminished immune response. Patients taking these medications have a reduced ability to generate protective antibodies compared to those not on immunosuppressive therapy. This reduction highlights the need for timely booster doses.
Corticosteroids
Corticosteroids, such as prednisone, can significantly impair the vaccine response, particularly at higher doses. Patients receiving high doses (more than 20 milligrams per day) may be at greater risk for a blunted immune response after the initial vaccine series. Patients on any immune-modifying treatment should be aware of the potential for reduced efficacy and prioritize getting additional vaccine doses as recommended.
Official Guidance on Timing and Scheduling
Medical organizations, including the American College of Gastroenterology (ACG) and the Crohn’s & Colitis Foundation, recommend that UC patients get vaccinated as soon as they are eligible. Guidance emphasizes the importance of vaccination while the UC disease is stable and in remission. Vaccinating during a flare is generally avoided, not due to safety concerns, but because an active flare indicates a highly inflamed immune system.
Patients should not interrupt their current UC treatment schedule to get the vaccine. Stopping a medication, especially a biologic or immunosuppressant, is considered riskier than vaccinating on schedule, as discontinuing therapy can trigger a severe disease flare. Gastroenterologists often recommend specific timing for patients on infusion-based biologics to optimize the immune response.
For those receiving intravenous biologic infusions, such as infliximab, the vaccine is often scheduled mid-cycle. This means vaccinating closer to the time of the next scheduled dose rather than immediately before or after the infusion. This strategy aims to maximize the immune system’s ability to respond before the drug concentration is at its highest. If mid-cycle scheduling is not possible, the advice remains to get the vaccine at the earliest opportunity.