On day 21 after the vaccination start, PA-STm-treated mice developed a S. Typhimurium-specific intestinal IgA titer that is equivalent to that observed at 3 weeks post-infection with the live attenuated strain S. Typhimurium M556, as determined by bacterial flow cytometry (45) (Figures 3A,B; Figure S1 in Supplementary Material). The gene discussed is CD79A; the disease is infection.