Rheumatic disease patients may require 2 doses of flu vaccine

Patients with inflammatory rheumatic disease may need 2 doses of adjuvanted split influenza A (H1N1) vaccine to elicit the same antibody response as healthy individuals, reported a recent Swiss study published in Arthritis & Rheumatism.

Antibody response to H1N1 vaccine was studied in 173 patients with inflammatory rheumatic diseases and 138 controls. Patients received 2 doses of vaccine and controls received 1 dose. Both groups achieved a significant response to the first dose; however, geometric mean titers (146 versus 340, P<.001) and seroprotection rates (74.6% versus 87%, P<.001) remained significantly lower in patients. A second dose markedly increased patients’ antibody titers, resulting in similar GMTs and seroprotection rates as reached with 1 dose in the healthy controls.

The main determinants of lower vaccine responses were increasing age, the use of disease-modifying antirheumatic drugs (DMARDs) (except hydroxychloroquine and sulfasalazine), and recent (<3 months) B cell depletion, but not tumor necrosis factor-α antagonists.

"A second vaccine dose enabled patients with rheumatic disease to achieve similar rates of seroprotection and antibody titers as controls," the researchers concluded. "The vaccine responses were not influenced by the nature of underlying rheumatic disease but rather by age and some types of treatment."