The innate immune response differs in primary and secondary salmonella infection.
This study examines innate immunity to oral Salmonella during primary infection and after secondary challenge of immune mice. Splenic NK and NKT cells plummeted early after primary infection, while neutrophils and macrophages (M{phi}) increased 10- and 3-fold, respectively. In contrast, immune animals had only a modest reduction in NK cells, no loss of NKT cells, and a slight increase in phagocyte
