*all p<0.0001 *all p<0.0001 SAT0037 Immune Response to Influenza Vaccination in Patients with Rheumatoid Arthritis Receiving Treatment with Biologic Agents N. Yuklyaeva1,*, D. A. Lawrence2, D. Raddatz1, J. Kasten-Jolly2, M. Scribani1, J. Victory1, J. Tirrell1, A. A. Chaudhary1, S. Sornprom1, A. Sanguankeo1 1. Bassett Medical Center, Cooperstown, NY, USA 2. Wadsworth Center, New York State Department of Health, Albany, NY, USA Bassett Medical Center Results *all p<0.0001 *all p<0.0001 Introduction Pearson correlation between baseline titer and titer at 6 weeks and 6 months post-vaccination (p<0.0001) Immune response to vaccination in rheumatoid arthritis (RA) patients is not influenced in the same way by biologic agents. After influenza vaccination, limited data in the literature is available to prove effective anti-influenza status at the end of the season. All subjects fulfilled the criteria for seroprotection by HIA (titer >1:40) prior to vaccination and only one patient failed to seroconvert (>4-fold increase) by the end of the season. ELISA analysis revealed more subtle dynamics of the immune response. The ANOVA model produced a statistically significant two-way interaction: a more moderate slope between pre-vaccination and 6 weeks post-vaccination among the Anti-T cell group as compared to the other two groups. µg 6 Weeks Post µg 6 Months Post All Subjects Combined µg Pre-Vaccination 0.79 0.80 Anti-T 0.93 0.85 TNF 0.81 0.82 Control µgs Pre-Vaccination 0.63 0.76 Objectives To assess the strength and duration of response to quadrivalent influenza vaccine California/07/2009(H1N1), A/Texas/50/2012 (H3N2), B/Massachusetts/02/2012, B/Brisbane/60/2008) in patients with RA receiving biological agents. Statistically significant positive correlations found between baseline titer and titer at 6 weeks and 6 months post-vaccination. Study Design Total (88) Conclusions Anti-T cell therapy may affect the strength and duration of IgG-mediated immune response and protection may fade away before the end of the influenza season. Response of patients on anti-TNF therapy was comparable to the control group. HIA reveals more subtle dynamics of the immune response. Clinical influenza infection was not reflected in the study and needs further investigation. Healthy Control (37) R.A Patients (51) TNF  Agents (35) Anti T Cell Agents (16) Measuring Antibody Titers Paired t-test revealed the significant increase from baseline to 6 weeks post-vaccination for the anti-TNF and Control groups, but not for the Anti-T-cell group. The decrease in titer from 6 weeks to 6 months was significant, and the overall change from baseline to 6 months was not significant for any group. Measuring antibodies by ELISA Using Hemagglutination Inhibition Assay (HIA) References Group Mean Change T1-T2 Mean Change T2-T3 Mean Change T1-T3 Anti-T 14.89 -40.68* -25.79 TNF 34.98* -36.43* -1.45 Control 35.13* -29.08* 6.06 Visit 1 - Baseline/prior to vaccination Visit 2 - 4-6 weeks post-vaccination Visit 3 - End of influenza season ( New ) Adler S. et al. Protective effect of A/H1N1 vaccination in immune-mediated disease-a prospectively controlled vaccination study. Rheumatology (Oxford). 2012 Apr; 51(4):695-700. Prevention and Control of Seasonal Influenza with Vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, 2013–2014. * P < 0.05