Vaccination Against Pneumococcal in Naïve Abatacept Rheumatoid Arthritis Patients

The study population will be all the RA patients between 18 and 85 years with instauration of a treatment by sub-cutaneous abatacept in association with methotrexate who agreed to participate to the study. At the time of their inclusion, patients will be randomized for receiving either pneumococcal polysaccharide vaccine (PPSV) or pneumococcal conjugate vaccine (PCV). The primary endpoint will be evaluated at one month after vaccination. The total of follow-up will be of 12 months. For the patients of the group PCV, the prime-boost strategy will be applied in order to be in accordance with the current French recommendation and a revaccination at 2 months after the initial vaccine will be realized with PPSV.