Aims:
* Evaluate the strength and duration of immune response after influenza vaccination in patients with Rheumatoid Arthritis (RA) receiving treatment with biological agents.
* Evaluate for predictors of immune response such as age, gender, disease duration, type of the biological agent(s) used, duration of the treatment, and type of treatment in the past.
* Assess the efficacy of vaccine response in this population by recording proportion of patients who contracted influenza illness despite vaccination. The result of the study may provide more information regarding which situations inadequate immune response by strength or duration would most likely to be expected. This may help lay some groundwork for future studies looking at the use of booster vaccinations in this population
