Crohn's and Colitis Canada Recommendations for Receiving Booster Doses of COVID-19 Vaccines

Older Gentleman receiving a COVID Booster


Summary of recommendations:
  • We recommend that people with IBD who are receiving medications that suppress their immune system (systemic corticosteroids, thiopurines, methotrexate, and biologics) have access to booster COVID-19 vaccines between 14–18 weeks after their second vaccine dose.

  • We recommend that unimmunized people with IBD receive the COVID-19 vaccine as soon as possible.  Vaccines have proven effective at preventing severe COVID-19 (hospitalization, death), even against variants of concern.

  • We strongly encourage employers and schools to consider mandatory vaccination policies so as to minimize the risk of serious and deadly COVID-19 in people living with Crohn's disease and ulcerative colitis.

On August 24, 2021, the Crohn's and Colitis Canada COVID-19 and IBD Task Force convened to discuss the issue of booster vaccines in people with inflammatory bowel disease (IBD). The Task Force members reviewed the latest pre-print manuscript (not yet peer-reviewed) from the CLARITY-IBD study, and research in people without IBD who have compromised immune systems. The CLARITY-IBD study demonstrated that people with IBD who are using anti-TNF biologic therapies generally responded well to two doses of either an mRNA vaccine (BNT162b2, produced by Pfizer/BioNTech) or adenovirus-vector vaccine (ChAdOx1 nCOV-19, produced by Oxford/AstraZeneca), although not as well as people using vedolizumab to treat their IBD (a biologic that does not systemically suppress the immune system). In addition, the concentration of anti-COVID antibodies in people using infliximab dropped below the level thought necessary to provide immunity approximately 14–18 weeks after the second dose, which was not seen in those on vedolizumab or in healthy controls. The authors concluded that people with IBD receiving systemic immune-suppressing therapy should carefully follow public health guidelines on masking and physical distancing and should be considered for booster doses to improve immunity.

Provincial governments in Canada are currently considering who should receive booster doses of mRNA vaccines. Potential recipients include seniors, people with cancer on active therapy, and people who have received transplants. Crohn's and Colitis Canada supports the Centers for Disease Control (CDC) recommendations that people on high-dose corticosteroids and other immune suppressing medications (including anti-TNF biologics) should receive booster doses. Systemic corticosteroids have consistently been associated with severe COVID-19 and death in people with IBD in the SECURE-IBD registry. There is emerging data (from the CLARITY-IBD study and SECURE-IBD registry) that IBD patients who are immunocompromised may be at risk for serious and life-threatening COVID-19. 

In light of this growing body of research, the Crohn’s and Colitis Canada COVID-19 and IBD Task Force recommends that people with IBD who are systemically immunosuppressed (using medications like systemic corticosteroids, thiopurines, methotrexate, or biologics) should have the ability to access booster COVID-19 vaccination 14–18 weeks after their second dose. Crohn's and Colitis Canada continues to recommend that people with IBD receive two doses of any COVID-19 vaccine available (whether they are immunosuppressed or not). These recommendations are particularly important during the fourth wave in Canada, when the Delta variant of SARS-CoV-2 is the predominant strain.

The Delta variant is spread more easily and is associated with an increased risk of hospitalization. Receiving two doses of an mRNA or adenovirus-vector vaccine is effective at preventing infection with SARS-CoV-2 and highly effective against severe COVID-19. Vaccine booster doses are a way of enhancing this immunity. In addition, we recommend that people with IBD use masks when indoors and ensure physical distancing when associating with unvaccinated people, or people with unknown vaccine status.


Approximately 1 in 140 people in Canada live with IBD, one of the highest rates in the world. Crohn's and Colitis Canada asks employers and schools to consider that most people with IBD are immunosuppressed, and may not mount as good a response to vaccination as other people (especially as immunity wanes over time). We must act to protect people who are vulnerable to COVID-19. Requiring employees, students, and teachers to be vaccinated is one of the best ways to prevent the spread of COVID-19.

Therefore, the Crohn’s and Colitis Canada COVID-19 and IBD Task Force strongly encourages employers and schools to consider mandatory vaccination policies so as to minimize the risk of serious and deadly COVID-19 in people living with Crohn's disease and ulcerative colitis. In addition, requiring masks while indoors, physical distancing, and proper ventilation will make workplaces and schools safer for vulnerable people, and for us all. 

For more information on COVID-19 and guidance for people affected by Crohn's or colitis, please visit our COVID-19 and IBD section.

  • Canada has among the highest incidence rates of Crohn's and colitis in the world.
  • 1 in 140 Canadians lives with Crohn’s or colitis.
  • Families new to Canada are developing these diseases for the first time.
  • Incidence of Crohn’s in Canadian kids under 10 has doubled since 1995.
  • People are most commonly diagnosed before age 30.

Other Areas of Interest