Immune response to pneumococcus and tetanus toxoid in patients with moderate-to-severe psoriasis following long-term ustekinumab use.

BACKGROUND: Little is known about the impact of long-term use of immunosuppressive agents on immune response. OBJECTIVES: Assess the impact of continuous maintenance ustekinumab treatment on patients' ability to mount immune responses to pneumococcal (T-cell-independent) and tetanus toxoid (T-cell-dependent) vaccines.