Objective: This study compared the immunogenicity of influenza and pneumococcal vaccines in adult patients with rheumatoid arthritis (RA) receiving adalimumab or placebo.
Methods: In this double-blind, randomized, multicenter study, patients received adalimumab or placebo on Days 1, 15, and 29. Pneumococcal and influenza vaccines were administered on Day 8 (vaccine baseline). Vaccine response (> or = 2-fold titer increase from baseline in > or = 3 of 5 pneumococcal antigens and > or = 4-fold titer increase from baseline in > or = 2 of 3 influenza antigens) and protective antibody titers (> or = 1.6 microg/ml pneumococcal antibody concentration to > or = 3 of 5 antigens and > or = 1:40 influenza antibody titer to > or = 2 of 3 antigens) were analyzed 4 weeks' postvaccination.
Results: Following pneumococcal vaccination, percentages of patients achieving a vaccine response were similar in the adalimumab and placebo groups [37.4% and 40.4%, respectively; 95% CI (confidence interval) -16.2%, 10.3%]. Percentages of patients with protective antibody titers were similar in both treatment groups (adalimumab: 85.9%, placebo: 81.7%). Following influenza vaccination, percentages of patients achieving a vaccine response were lower with adalimumab than placebo (51.5% and 63.3%, respectively; 95% CI -25.2%, 1.6%)--a result explained by the subgroup of patients with preexisting protective antibody titers at baseline. For patients without protective antibody titers at baseline, response rates were similar in the 2 groups (adalimumab: 73.3%, placebo: 73.9%). Percentages of patients with protective antibody titers were similar in both treatment groups (adalimumab: 98%, placebo: 94.5%).
Conclusion: Patients with RA treated with adalimumab can be effectively and safely immunized with pneumococcal and influenza vaccines.