One or Two Week Methotrexate Discontinuation on Efficacy of Influenza Vaccination in Rheumatoid Arthritis.

Inclusion Criteria:

• Males or females ≥ 19 years of age at time of consent
• Have a diagnosis of RA per ACR criteria
• Must understand and voluntarily sign an informed consent form including writingconsent for data protection
• Stable doses of methotrexate over the preceding 6 weeks

Exclusion Criteria:

• Pregnant or lactating females
• Previous anaphylactic response to vaccine components or to egg.
• Acute infection with T >38°C at the time of vaccination
• History of Guillain-Barre syndrome or demyelinating syndromes
• Blood transfusion within 6 months
• Any other rheumatic disease such as systemic lupus erythematosus, mixed connectivetissue disease, dermatomyositis/polymyositis, and vasculitis except for secondarySjogren's disease
• Any condition including laboratory abnormality which places the subject atunacceptable risk
• Subjects who decline to participate