Trial of High Dose vs. Standard Dose Influenza Vaccine in Inflammatory Bowel Disease Patients

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract which includes Crohn's disease (CD) and ulcerative colitis (UC). A recent epidemiological investigation estimates that nearly 4 million people worldwide are affected and approximately 1.4 million of these cases occur in the United States. IBD can lead to debilitating symptoms, hospitalizations, decreased quality of life, frequent procedures and/or surgery. Treatment options consist of immunosuppressive therapy, such as systemic corticosteroids, immunomodulators (thiopurines and methotrexate) and/or biologics, such as tumor necrosis factor alpha (TNF) agents or an integrin inhibitor, vedolizumab. They can achieve clinical remission and decrease the risk of complications, but also increase the risk for opportunistic infections, including influenza. Multiple studies have shown lower influenza vaccine responses in patients with IBD compared to healthy individuals; IBD patients treated with TNF agents or combination therapy (TNF inhibitors and immunomodulators) are very likely to mount a poor immune response. Influenza serum antibody concentration correlates with protection from infection following vaccination. Therefore, increasing influenza antibody responses in patients with IBD would appear to be critical to improving protection from influenza. A high dose (HD) influenza vaccine containing four times more hemagglutinin was licensed based on its ability to induce higher antibody concentrations compared to standard dose (SD) in adults 65 years or older.