Cytokine production from SIN lymphocytes in response to 6MHP stimulation in 3 patients with prior vaccinations. The SIN responses for 3 patients from prior type I vaccine studies. SIN lymphocytes from pre-vaccine lymph nodes were cultured with the 6MHP, and supernatants were harvested at 40-48 h, and then evaluated with cytokine bead array (CBA) for levels of Th1 and Th2 cytokines. The SIN lymphocytes from the same patients were evaluated with cytokine bead array after 3 doses of 6MHP vaccination. Notably, prior vaccination with type I peptides does not seem to preclude a response to type II peptide vaccination.