In a letter published in Gut, Dr. Kevan Jacobson, Dr. Pascal Lavoie and collaborators from the University of British Columbia report modestly lower antibody levels in adolescents, aged 12 to 17 years, with inflammatory bowel disease (IBD) who are on the anti-TNF-a anti-inflammatory therapy infliximab in combination with other immunosuppressive drugs or given as monotherapy, after a first dose of Pfizer-BioNTech’s Comirnaty vaccine. However, this divergence disappears after the second dose. These findings underscore that most youth with IBD receiving these therapies elicit adequate antibody responses following a complete COVID-19 vaccination.

Youth with autoimmune conditions such as inflammatory bowel disease (IBD) were excluded from vaccine trials. It is unknown whether the immune modulating drugs taken to manage IBD impedes the antibody response to COVID-19 vaccines.

Participants in this study were stratified into two groups based on their IBD treatment profiles: 1) treated with the anti-inflammatory drug infliximab (N=29), and 2) treated with infliximab in combination with an immunosuppressant, precisely methotrexate or azathioprine (N=38). A group of not previously infected, healthy adults (N=20) was used as a comparator.

Key findings:

  • Adolescents with IBD treated with infliximab monotherapy had modestly higher levels of antibodies against SARS-CoV-2 spike and receptor-binding domain (RBD) 28 days after their first vaccine dose compared to adolescents with IBD treated with infliximab in combination with another immune modulating drug.
  • In adolescents who received two doses of the vaccine, there was no discernible difference in anti-spike or anti-RBD antibody levels (measured at three months post dose one) between adolescents with IBD on combination therapy, adolescents with IBD on infliximab monotherapy, and healthy adults.
  • When looking at neutralizing antibodies, adolescents on combination therapy for IBD had inferior antibody neutralizing capacities compared to both their counterparts in the monotherapy group and healthy adults three months after the first dose, though neutralization was still detectable.

Antibody levels for SARS-CoV-2 spike, RBD, and nucleocapsid protein were measured at time of enrollment (i.e., baseline) and at 28 days and three months after the first dose. Antibody neutralization against the wild-type strain of SARS-CoV-2 was assessed three months after the first dose.

It is important to continue to monitor vaccine effectiveness in this vulnerable pediatric population to ensure that they remain adequately protected.

Shire ZJ, Reicherz F, Lawrence S, Sudan H, Golding L, Majdoubi A, Levett PN, Lavoie PM, Jacobson K. Antibody response to the BNT162b2 SARS-CoV-2 vaccine in paediatric patients with inflammatory bowel disease treated with anti-TNF therapy. Gut. 23 Nov 2021. doi: 10.1136/gutjnl-2021-326196