Annual vaccination against influenza is recommended for those at high risk of complications, particularly among patients with immunodeficiency including those resulting from immunosuppressive treatments administered for a chronic inflammatory bowel disease (IBD). However, published data showing that influenza vaccination coverage is low in this population (<30%) due to lack of data on the effectiveness of vaccination in these patients and the theoretical risk of negative impact on the evolution of IBD.~To improve influenza vaccination coverage of the population treated by immunosuppressants for a chronic IBD, it is essential to have data on the effectiveness of vaccination in these populations.~The research aims to evaluate the immunogenicity of influenza vaccination in patients followed for a chronic IBD.~Factors in choice of study population were as follows:~IBD is a common disease. Among the inflammatory diseases treated with immunosuppressants and reaching patients under 65 years, IBD are among the most frequent. They result from an abnormal immune response to gut flora and their management often requires the prescription of immunosuppressive drugs (azathioprine, methotrexate, in particular) and more recently TNF-blockers;~the existence of vaccine recommendations published recently for specific patients on immunosuppressive therapy at greatest risk of complications related to influenza;~the fact that vaccinations have not been implicated in the pathogenesis of the disease;~data showing that vaccination recommendations are poorly followed in this population. A recently published work found vaccination coverage against influenza of only 28% in a cohort of 169 patients treated for IBD;~The methodology chosen is a phase III, prospective, open, vaccine trial. The primary endpoint is the humoral immunogenicity induced by the vaccine.~The study is scheduled on 2 successive years to assess the value of annual vaccination repeated in this population treated with immunosuppressants.~There is a benefit for patients to participate in this study because they are all vaccinated against influenza and will benefit from a clinical and laboratory monitoring in this study. Moreover, these patients are taken to be vaccinated in the event of a pandemic influenza
The primary purpose of the study is to compare the efficacy and safety of influenza vaccine in patients with inflammatory bowel disease (IBD) receiving immunosuppressive therapy with patients not receiving immunosuppressants .~The main objective of the study is to evaluate the humoral immunogenicity of influenza vaccination in patients with IBD