Immune responses following administration of influenza and pneumococcal vaccines to patients with rheumatoid arthritis receiving adalimumab

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 (>= 2-fold titer increase from baseline in >= 3 of 5 pneumococcal antigens and >= 4-fold titer increase from baseline in >= 2 of 3 influenza antigens) and protective antibody titers (>= 1.6 mu g/ml pneumococcal antibody concentration to >= 3 of 5 antigens and >= 1:40 influenza antibody titer to >= 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.