When vaccines first became available for COVID-19, 70% of surveyed people with inflammatory bowel disease (IBD) expressed concerns about side effects.

Crohn’s disease, ulcerative colitis and other forms of IBD are chronic conditions that occur when the intestinal immune system becomes overreactive, causing chronic diarrhea and other digestive symptoms. Because immune system malfunction is one possible cause of IBD—and patients are often treated with immune-modifying medications—patients also worried that vaccines might not produce a sufficient immune response to protect them against COVID-19. But recent Cedars-Sinai research should ease their minds and digestive systems.

The study revealed that IBD patients receiving immune-modifying therapies were not at risk of increased side effects from the Pfizer-BioNTech or Moderna COVID- 19 vaccines. More than 90% of IBD patients produced antibodies in response to COVID-19 vaccines, regardless of vaccine type and whether they were taking immune-modifying medications, according to Dr. Gil Melmed, director of Inflammatory Bowel Disease Clinical Research. However, IBD patients receiving the Johnson & Johnson vaccine developed significantly lower antibody levels than those receiving the two other vaccines.

"The mRNA vaccines may have a more potent mechanism for inducing antibody response," Dr. Melmed says of the Pfizer and Moderna vaccines. "And because they are delivered in two doses, rather than one dose like the Johnson & Johnson vaccine, they provide two immunological hits."

Read: COVID-19 Vaccine and IBD and Cancer