The primary aim of this research are to measure seroprotection in IBD patients who are on or off immunosuppressive agents after receiving the influenza vaccine. The hypothesis is that IBD patients on immunosuppression have impaired immunity, and therefore, will have a lower seroprotection rate after immunization compared to IBD patients not on immunosuppression. If data is available, we will also compare each group to historical healthy controls given the same vaccine. The secondary aims are to determine the antibody titer levels and side effects these patients have.